Minerals of Rockbridge County, Virginia

Home , Celadonite, Gibbsite, Rozenite, Taaffeite

VOL. 40 FEBRUARYJMAY 1994 NO. 1 &2

MINERALS OF ROCKBRIDGE COUNTY, VIRGINIA

D. Allen Penick, Jr.

INTRODUCTION

RockbridgeCountyhas agreatdiversityofrocksandminerals.Rocks withinthecountyrangeingeologic agehmPmxnbrianthroughDevonian (01desttoyoungest)covexingatimespanofatleast 1OOOmilIion years. The county liesmostlywithintheVdeyandRiagePhysi~hich~~ 1). Thisprovinceis underlainbysedimentaryrochcomposedof dolostone, limestone, sandstone, andshale. TheexlMlceastempartofRockbridge County is withintheBlueRidge PhysiowhicPro. This areaisrepre sentedbyallthreemajorrocktypes: sedirnentary,igneous, andmetarnorphic. Theseinclu&Qlostone,qdta,inta~s~neandshale,granite, pmdiorite, andunakite. Ingeneral, theol&strocksarefoundin theeastem portion with youngerrocks outcropping in the westernpart of thecounty o%w2). Mininghasplaydan~tpaainthehistoryofRockbridgeCounty. Indians probably were thefirstco1lectorsof localqu~andquartzitefrom which they shapedprojectilepoints. Important deposits of ironore were mined in the 1800s near the towns of Buena Vista, Goshen, Vesuvius, and in Amoldvalley. Other early minesin thecounty -&manganese, waver- tine-marl, tin, niter (saltpeter), lithographiclimestone, silicasand, andcave orryx Thecounty has been prospected for barite, gibbsite (alumina), gold, silver, limonik(ocher),beryl, Ghalerite (zinc), andilmeniteandmtile(titanium), but no production has beenreported for t.Quarriesare still producing dolostone.lirnestone, andquartzitefor constructionaggregate andshale forbrickmanufacture. This report describes 102mineralsandnativeelements which havebeen reported from the county. Rockbridgecounty is one of the more prolific Figure 1. LocationmapofRockbridgeCounty, Virginia. mineralcollectingareas in Virginia. A large percentageof the mineralsare concentratedin threeareas: in the tin deposits near the headwatersofIrish they areassociatedwithmanyofthemineralsfoundthecounty. -is Creek; thevesuvius iron-manganesedistrict; andin thehneJackquarry ametamorphicrockfoundinscatteredoutcropsalong Big MarysCreek, near Glasgow. InadditionBxger'slimestonequqoutsideLexingtonhas LittleMarys Creek, andIrish Creek. It is composed mainly of pink to red producedexcellentpyritecrystalsandothernotewyminerals. Unusual feldspar, green epidote,and gayquartz along with other mine& in minor qwtzcrystals havebeen foundnear Collierstown, HouseMountain,&Hog amounts. Unakiteisanathactiverockwhenpolishedandisusedf~~omamen- ~ack~ountain.~rareminerd,rockbrid~eite, was first foundin andnamed taldemrativepurposes. ~mberliteisa~kigneousintrusiverockfoundin for Rockbridge County. It wasrecognizedasadistinctmineral species in twoseparatebodiesnearMt.HorebChurchin thesouthwestem partof the sampleshmtheMidvaleironminesouthofVesuvius. county. Kimberliteisconsideredthechief sourcerock Inadditionto l02mine1alspecies, threerelativelyrarerock&xsalso wide. Nodiamondshavebeenfoundto- howevera shouldbernentioned.These~~~hwillbediscussd~uentlyinthereportas mineralsare found inthesedeposits. Thesemerocktypes were VIRGINIA DIVISION OF MINERAL RESOURCES Vol. 40

MINERAL SPECIES AND ELEMENTS

ACTINOLITE - AMPHIBOLE GROUP (hydrouscalcium, magnesium, iron silicate). Actinoliteisawmmon~inmetamarphic~~~ksrichinh andmagnesium. It is foundas fibrous massesreplacingpyroxene group mineralsinthem~rposedgranodioritemundtheIrishCreektindeposit (Glass andothers, 1958).

AlKMTE(lead,copper,bismuthsulfide). Thisrarebiimuthrnind~s &theIrishCreektindepositasblackishgray acicularcrystalsassociatedwith carbonateminerals (Glassandothers. 1958). Thecrystals haveametallic luster and yellow tarnish.

ANATASE (titanium oxide). Microscopiccrystals of anatase havebeen foundinstylolite-lieclay seamscutting quartziteinHellgatecanyon two miles southwestof theJamesRiveratGlasgow(L 1966).

manufacture.

EXPLANATION MILLION YEARS AGO

DEVONIAN SILURIAN 425 365

[7 ORDOVICIAN 500 425

CAMBRIAN 570 500

I:=:( PRE CAMBRIAN 1000+

THRUST FAULT

Figure2 General gmlogicmapofRockbridgeCounty,Virginia(modified EXPLANATION a€terButts. 1933).

0 descriiby Spencer(l968). Greiseqis analteredgraniticmckwmposed Caved* shaft mainly ofquarizand mica Topaz,usually foundingreisen,isnot~fmm Aplits Portal X thislocality. Cassitaite,thechieforeoftin,isfoundalongtheborderbetween 0 Pl t thegreisenandthegranodioritecountryrockatthedepositnearhhCreek Grsnodvorlte lrzch 'Ihesemines,alsololownastheCashmines,consistofthenumber 1workings on Panther Run and the number2 workings locatedon theridgeabout 1200

feettothesouthwest(Figure3). 0 Feet Most of the localitiesdescribedin this report havebeen fieldchecked. 'Ihmnotcheckedhavebeenreclaimedortherewasnotenoughinfmation available to locate the site in the field. It is very important that a . collector obtain the permission of the property owner before entering a locality to collect minerals. "Entering private osch property without permission violates trespass laws and is punishable by law". Forthesakeof conveniencethemineralsinthisreport arelistedalphabetically. The author would like to express his appreciation tothefollowingper- iron, magnesium, carbon- sonsfortheirassistanceinpreparingthisreport RichzndV.Diebrich, Howard aggregates with fluorite, R. Freeland,?homas M. Cahight,II, Wfiam F. Gi- lassandothers, 1958).It Jr.,VernonN. Morris,andRoy S. Sites. No. 1 & 2 VIRGINIA MINERALS

ARAGOm-ARAGONITEGROUP(calciumcarbomte). Arago- beryl prisms are bent and many are fractured. The fractures are filled with nitecanbefoundin~lyallcavesinVir~Nospecificlocalitiesaregiven. flouriteandquartz. Theyellowberylmaybeassociatedwithphenakite(G1ass Thereareapproximately91 caves inRockbridgeCounty (Douglas. 1%4). andothers, 1958).To the writer'sknowledgeno gemqualityberylhasbeen fdfmmthislocality. @ ARSENOPYRlTE(anmicsulfide). Arsenopyriteoccursinsilvery whiteto During WorldWar II, theBethlehemSteel Corporation wnductedan grayishveinstwo or moreinches across in quartzandgreisenat theIrish investigationfor beryl andtininthis area. Creektindeposit. Itisoftenfoundwithcassiteriteinthegreisen.Themineral hasame~clwterandisthem~~tab~tsu&thesiMuchofthe BIOTITE - MICA GROUP (potassium, magnesium, iron, silicate). Green arsenapyriteisgoldbearing (seegold). biotiteisfairly abundantinthecounhyrockattheTrishOektinminesinthe east-west tunnel of thenumber 1workings. Itisassociatedwiththegreisen AUGITE-PYROXENEGROUP(calcium,sodium,magnesium,iron, alu- andmay repmentalterationofbrownbioti~ minum.silicate). Augiteisthe~pyroxeneMinthe~Orite (Glassandothas,1958). country rocknear theIrishCreektin mines whereit occurs as lath-shaped crystals(Glass andothers, 1958). BIRNESSITE (sodium, manganese, oxide). Birnessiteoccurswithother blackmanganeseoxideminerals collectedhm thedumpsof theKelly Bank BARllX - BARZTEGROUP(bariumsulfate). AtthehneJack quany near minenearVeswius(MitchellandFreelan4 1978). Glasgow, twofmsofbaritecrystalsarefound:thin tabularcolorlesstobluish andthicktabularwhite,aeam,oryellowish(Figure4). Associatedrninerals BISMUmE (bismuth carbonate). At theIrishCreektinmines this rare, arecalcite,&lmite,andmite@ietrich, 1985). white,submetdicmbomtemineralwasfoundina6-inchwidequartzvein Smallcleartabularbaritecrystals occur incavities in limestone with thatcutsthegreisen. Thelocationisapproximately 15 feetwestoftheaditat calcite and quartz crystals at Barger's Quarry near Lexington. A barite thenumber1workings(samplebyW.F.~,X-ray identificationby0.M. crystal from the quarry can be seen in the Washington and Lee University -1. geologycolktion(Penick, 1987). TheJohnsonbariteprospectislocated0.75 milenorthof theBotetourt- CACOXENITE (hydrous iron phosphate). Cacoxenite occurs as golden Rockbridgecountyline,andO.25milewestofU.S.Highway 11. Fragments yellow fibers in cavities inrockbridgeiteat theDixie minenear Vesuvius. of white and dark gray barite were uncovered while repairing alocalfarm Associated minerals are stnmgiteandkidwellite.It also formsradiig bursts road(Edmundson, 1938). andresinousglobules in ironore at theDixie mine (BarwoodandZelazny. TheBecktelprospectisrepoaedtobelocatedapproximately4miles 19w southof Lexingtonand0.5 mile westof U.S. Highway 11, (exactlocation AttheKellyBankmine,onemileeastof\resuviw, mxeniteoccursas unknown). Theprospectconsistsof smallbarite fragmentsassociatedwith golden yellow fibers inmanganianoxideore(PaulDesautels,personalcom- chat probably fromtheBedmantownFormation(Edmundson, 1938). munication, 1%2). This mine has beenreclaimed. The mineral is also found TheShorterprospectislocated0.5milenorthwestofRappsMillinthe withrockbridgeite 1Omileseastof Lexingtonnearthecrestof SouthMountain southwestempartofthecounty. Theprospectconsistsofafew shallow test nearMidvale(Koening, 1877). Thisoccurrence wasprobablyattheMidvale pitsandscatteredfragments~Wte(Edmundson,1938). mine Awhitebaritevein 18incheswidecuttinggraniteisreportedeastofthe naturecamponBigMarysCreek,3mi1essouthoNesuviw. Specificgravity CALCITE -CALCITE GROUP (calcium carbonate). Calcite isawide- testsrunonasampleindicaksthattheveinispurebdte(Steidtmann, 1940). spread mineralin the limestone formations of Rockbridge County. Most This occurrencehas notbeen locatedbythe writer. calciteoccurs as white masses andveins that cut thepre-existing carbonate rocks. Twooperating quarries in thecounty have roducedexcellentex- amplesof calcitecrystals. 4 AttheLoneJackquarry bluish, or yellowish,vitreous, withobtuserhombohedral terminations; (b) colorlessto wh&to yellowish, translucent and substransparent, scalenohedralcrystals(dog-tooth spar)5- 300mmlong (Figures); (c) white,pearly,fibrousmasses;(d) oolorless,vitreous, transparent,p&maticcrystals up to 10mrn long;and(e) colorless,vitre- ow,pearly,and~entscale~)hedralcrystalsupto15mm long(Dietrich, 1985). CalciteattheLoneJackquanycommonly occursinveinsandcavities inhtoneanddolostonewithdolomite,pyrite,marcasite,Mte,fluoriteand palygorskite(Figure6). At Barger'squany east of Lexingtoncalciteoccursbothasveinsandin well formedcrystalsin limestone(Figure7). Clear, lustrousrhombohedral crystals to03inchesaaoss havebeen foundassociatedwithqa fluorite, andrarely,barite(Penick, 1987). Somecrystalsaregray to smokyinappear- ance.

CASSITERITE - RUTILEGROUP(tinoxide). Cassiteriteisthemajorore Figure4. White, blocky baritecrystals with dolomite, calcite, andpyrite, oftinandthemostimportant mineralat theIrishCreekdeposit.Itoccursas largestbdtecrystal0.2imh.hneJackquanynearGlasgow,photographby brown lustrous short pyramidalcrystalsin greisen next to massivequartz T.M. Gath~ight,II,courtesy 0fR.V. Dietrich. veins (Figure 8). Whitecassiterite has also been reported fkm thesedeposits (Ulke, 1894). Themineralisalmostalwaysassociatedwith gray quartzand BERYL(beqllium silicate). Beryloccm inthegreisenatthekishcreektin muscovite. It is often found with siderite and may beconfused with that deposits as slenderhexagonal prisms from 1to5 mrn long andabout 2mm mineral. However,distinctcleavage,high~~cgravity, andpolysynthetic acr0ss.Mostoftheberylispale~butsomeisyellow.Someofthe- twinningdistinguishcassiteritefromsid~sandothe~~,1958). Cassi- 4 VIRGINIA DIVISION OF MINERAL RESOURCES Vol. 40 teritealso forms veinlets, lenses, andirregular cornpactmasses. A few clear CHALCOPmE-CHALCOPMiTTEGROUP (mpper,iron, sulfide). gemquality crystalshave been found. Chalcopyrite issimilartopyriteinappearmcmdis foundassmallyellow crystalsandirregulargxainswithbismuthsulfides adjacenttosideriteveinsat CELADONITE -MICAGROUP@otassium,magnesium,iron,aluminum, theIrishCreeactindepwits. Itisalso foundwithpyrrhotiteinthe-nume silicate). At theLoneJackquanynear Glasgow celadoniteoccursas green (Glass andothers, 1958). Small masses of chalcopyriteassociatedwith coatingson shear zone surfaces and pints in carbonaterocksThemineral malachite, microcline, and magnetite are foundin unakitealong IrishCreek wasidentifiedbyx-rayanalysis(Dietrich 1985). severalmilessouthofthetinminearea

Figure 6. Scalenhedralcalcitecrystals,some withacoating of small pyrite crystals, Lone Jackquany, specirnen4in~hesacr0~~;ph0tographbyT.M CHURCHITE (hydrous yimiumphosphate). At the timeof itsbveryat 0 Gathright,II. fheKellyBankminein 1944churchitehadonlybeenverifiedhrnoneother No.lt2 VIRGINIA MINERALS 5

localityinthe world (Milton andothers, 1944). Atthat timechurchite was DUFRENITE (ironphosphate). Muchof the dufrenitedescribedin early knownas weinschenkite. Themineraloccurs as snow-whitefibrous aggre reports is actually rockbridgeite. However, recent studies by Keams and gatescoatingbrownsiliceouslimo~teorblackmang&oxide. Thewhite Penick(1989)show thatdufrenitedoesoccurwithrockbxidgeiteattheJXxie fibers have asilky luster and make attractive specimens against the dark ironminenear Vesuvius. It is foundas thin, darkbluish-green layers sand- &m~.~aggre~~asspWtesuptosevaal~e-wichedbehveenlayersof yellowishkidwellite. Otherassociated*se ters in diameter. An excellent specimen of churchite can be seen in the strengite and rockbridgeite. Identification of dufrenite was based on WashingtonandLeeUnivasitygeologycollectioninLexington. mim~~r~piccompaxisonwithlrnownmatd hm Char,keeCounty,Ala- bama and X-ray powder diffraction patterns. This is the first verified CLAUD~(menicoxide).Claudetiteisacolorlessto whiteseco- ocmrenceof dufrenitehmvirginia. mineral formedby theoxidationofaresenicmine. It is foundin association witharsenopyriteatthe~Creektinmines(specimenNMNH#139820of theSrnithsonianInstitutionwllection,Dietrich,1990). County. It is oneof themajor constituents of the unakite thatis foundin CLINOZOISITE - EPIDOTE GROUP (hydrouscalcium,aluminum,sili- outaopsandstreamsalongIrishCreek,Big Marys Creek,andLialeMarys cate). ClinomisiteisararemineralintheIrishCreekdistrictand0cc~~s in Creek. Pistachio-greencrystalsofqidoteup to0.4in pinkishgray clustersof slenderflatcrystalsfrom2to3mmlong. Itis foundin foundinq~veinscuaingdtein theoldqua 15 aveinlet(0.25 inchwideand7feetlong) cutting ashear zoneinthebaseofthe miles east of Vesuvius. At theIrishCreek tindepositqidoteoccursinthe east-westtunnel(number1 workings). Itisassociatedwithchloriteandcalcite metamorphoric~oritecountyrockandasrelictsin greisen(Glassand in greisen (Glass andothas, 1958). others, 1958).

COmAP~(hydrousironsuIfate).Copiapiteoccursas yellowishpowday EPSOMlTE(hydmusmagnaiumsuIfate).Epsomiteoccursaswhite,peraly, masses with paracoquimbiteatthe Kelly Bank mine near Vesuvius (R.S. transluscent,acicularcrystals up to 5 mmlongondo1ostoneattheLoneJack Mitchell'snotes). quarrynearGlasgow(Dieeich,1985).

CRYPTOMELANE -CRYPTOMELANE GROUP (manganeseoxide). FELDSPAR GROUP. Feldspar group minerals, (seemicroclineandortho- Cryptomelaneoccmas blackbotryoidaltonodular masses attheKellyBank clase) arecommoninigneousandmetamorphic~~~ksoftheBlueRidgearea mineneraVesuvius(MitcheUandFreelan4 1978).

DIOPSIDE -PYROXENE GROUP(calcium,magnesium, silicate). Diop- FERROHORNBLENDE -AMPHIBOLE GROUP (calcium,iron,magne sideis found as small greenchromiumrich grains in samples taken from a sium, alumimum, silicate). Ferrohomblendeisfoundas blackcrystalsinthe kimberliteoccure~lcenearMt.HorebChurchinthesouthwestempartofthe &ranodioriteattheIrishCreektindepOsit,(Glass andothers. 1958). county. ~ssociatedmineralsareilmenite,~hlo~opite(mica),talc,&ntine, pyro& (gamet),andspinel (X-ray analysesby 0.M. ~ordham). FLUORAPATITE -APATITE GROUP (calcium, fluorine,phosphate). a Fluoraptiteismmonbothhgranodioriteandh~eisenattheIrishW DOLOMITE - DOLOMITE GROUP (calcium, magnesium,carbonate). tin depositwhere it is associatedwithavariety of accessorymind (Glass Dolomiteisfoundascolorlesstowhite,pink, andwhitetobuffrhombohedral andothers. 1958). crystalsand saddleshaped groups at thebneJackquany (Figure 9). It is foundwithcalcite, barite, fluorite,pyrite,marcasite, andpalygdteincavi- FLUORITE (calcium fluoride). Fluoriteis foundin Barger's quarry near ties in thedolostone hostrocks (Dietrich, 1985). Dolomite is also amajor Lexington as purple topinkcubiccrystals up to 0.25 inchacross associated constituentofdolostoneinotherareaswithinthecounty. withcalcite, quartz;,andrarely,barite. Fluoritealsooccmaspurp1e"smears" on slickensidedsurfaces(Penick, 1987). Fluorite isoneof theminciDalmineralsof the neisenattheIrishW tindeposit. ~ostofthe fluckteisknegrainedandis white, colorless.orpurple. It penetrates fissures and fractures of the quartz veins and in places cuts through berylandmuscovite. It is not foundinthecountry mk(Glassand others, 1958). At LoneJackquarrynear Glasgow fluoriteoccursascolmless,yellowish, orpurple, transparent crystals. Someof thecrystalsaremned yellewish to purplish tocolorless (Dietrich, 1985). Fluoriteoccursboth with the host dolostoneandincavitiesinlimestonewithdolomite,calciteandpyrite.

GALENA(leadsuIfi&). GalenaisfoundasbrightrnetaJlicgmhsingreisenat IrishCreek(Glassandothers, 1958). Itisalsofoundinlimestone2mileswest ofLexington(Dana,1892);andassmalloctah~and"disdflat~W at thelone Jackquarry near Glasgow (Dietrich, 1963).

GALENOBISMUmE(lead, bimuth,sul€ide). Thisrarebismuthmineral occurs in thin, lead-gray to tin-whitelath-likecrystalswith sideriteandmusco- viteatthenumber 1 workingsattheIrishCreek tinmines. Itisalsoassociated withaikinite. Ithasametallicluster and develops yellow iridescencewhere exposedto weathering (Koschmannandothers,1942).

Figure'). Pink, saddle-sh+ddo~tecrystalswith&gof smallpyrite GARNET -GWGROUP(iron,aluminum, silicate). Unidentifiedgs- crystals, specimen4inchesacross;photographby T.M.Gathright, 11. netcrystals, probably almandine, can be foundas darkred, weathered, and 6 VIRGINIA DIVISION OF MINERAL RESOURCES frachnedcrystal masses in several roadcuts along StateRoad603(X-ray tedby H.L.GrowofRockbridgeCounty. analysesby~.~.~ardham). Theaystak, withanaGeragesizeof0.2inch,& foundhfekite,arockcomposedprimarilyofquaxtzarsd feldspar.

GIBBS~(hydr0usaluminurnoxide).Gibbsiteisthemaincomtituentofthe bauxite~itsfoundalmg~MineRunabout2miles~tofBuena Vista (Warren andothers. 1965). The mineral is oneof the main ores of ahuninum

GOETHlTE(ironhydroxide). Goethiteisafairly commonmineralwhichis foundinmost of theironandmanganeseminesscattered throughout the county. Themineraloccurs generally as either brown to black rounded masses or inradiating fibrous aggregates. Itwas themain ore mineral at the Dixiemine,whereitwasdepositedwithmckbridgeitein afaultzone. Itcouldpreviously bef0undwithmanganesemineralsattheKeUyBank mine, whichhasbeenreclaimed.Mteisbeing foundinsomeof theoldiron mines along Brattons Run in the western part of the county; these mines snppliedironoletothe~~~ceandktotheVic~fumacein Goshen. Other goethitel~tiesinclu&theoldLochersilicaquany afew milessouthof Goshen, Marys Creekmine,HogpenHollow mhe,Midvale Figure 11. Spider-shapedgraupsof gypsumcrystalsondol(-20X). mine, andtheJordanminenaBuenaVista. Bloodredtoiri&scentcopper fromLoneJackquanynearG1asgow;courtesyofR. V.Dietrich. brown~tinegoethite"buttom"~~~~~withcalcitecrystalsatLoneJack quany near Glasgow (Figure 10;Dietrich, 1990). Goethitealso is amajor constituent of thepseudormorphs after pyrite (goethite after pyrite) from HALLOYSITE- KAOm-S~PE~NEGROuP(hydr0usalumi- Barger's quarrynearLexington(Penick,1987). num silicate). Veins of halloysiteandkaolinite arefoundin fractures in the Cambrian-ageAntietam@min)quartziteattheW. C.Mathewsquanynear Natural Bxidge Station (Leonard, 1962).

HEMATITE - HEMATITE GROUP (iron oxide). Hematite is aheavy, reddish-browntoblackmineralwithadistinctivedeepredstreak. Itisthemost important ore of iron. It can be found in many of the iron mines located throughoutthecountygdy associatedwithgoethite-liinite. Hematite isfoundonYankeeHorseRidgeashematiticboxworkswithpyrite,amnopy- rite,andgold(Sweetandothers, 1989). C ItisalsofoundintheoxidiziedzoneoftheIrishCreektindepositasan alterationproductof titanium-richmagnetite(Glassandothers1958).

HEXAHYDRlTE (hydrousmagnesium sulfate). Hexahydriteis foundas colorless, acicular, white,c~ystallinepwderandpowdery~mdol~ Figurelo. Bloodredtocopper-browngoethite"but@m" etchedfromcalcite attheLoneJackquanynearG1asgow(Dietrich, 1963). crystals fromavugin theLoneJackquany(5OX);photographby G. K. McCauley,courtesy of R. V. Dietrich. HYPERSTHENE - PYROXENEGROUP (magnesium, iron, silicate). Hyperstheneis the most abundantpyroxene in thegranodioriteh GOLD -NATIVE ELEMENT. Samplesof arsenopyrite from theIrish Creektindeposits(Glassandothers, 1958). Creek tindeposit haverecently been fireassayedandshow values of 7.796 troy ouncesof goldperton(SweetandLovett, 1985). Oldreportsof 'The Virginias" (1884,~.38) also describehighassays inboth goldandsilver in clay mineral occurs frequently as inclusions in quartz crystals near samplesofmenopyritetakenfromthaemines. Goldisintimatelyassociated Collierstown(X-ray analysisbyR. S.Mitchell). with thearsenopyriteandcannotbe&tectedbyvisualinspection. Goldhas been identifiedin soil samples by geochemicalmethodson ILMENITE -1LMENITEGROUP (iron, titanium,oxide). YankeeHorseRidgeheernilessouthwestofthetin mines(Goo4 1991). The Ilrnenite along withrutilewasdiscoveredin 1939on theRobinsonGapmad highestconcentrationin thesoilsamplesrangedfromO.33toO.5 1 partsper about2miles southeastofBuenaVista Theilmenite-~tiledepositoccursas million. Samplesofthefekicqu~monwniteMockassay up to0.17 troy blackbandsinterWwithdh-brownqu.Themineralizedzone ouncespertonof goldor5.8partspermillion. is 15feetthickandcanbetracedfor adistanceof 0.25 mile. Other minerals foundinthequartziteincludequartz, feldspar, apatite, tourmaline, andziram GRAPHITE- NATIVEELEMENT. Graphite~~~masblacktosteel-gray (BloomerandDeWitt, 1941). Ilmenitealsooccursas grainsingreisenand dissminatedgrainsinfelsicgneissonNenleMountainm. S. Good,personal granodioriteat theIrishCreek tindeposit(Koschmannandothers. 1942). mnununiotion). Magnesium rich ilmenite is reported from the kimberlitenear Mt. Horeb Church (SearsandGibert, 1973). GYPSUM(hydrousca1ciurnsulfate). Singlecrystalsandradialgroupsup to 5 mrnacrossoccuronjoint surfacesintheargillacmusdolostoneat LoneJack JAROSITE(hy&ouspotassium,iron,sulfate). Jarosite hasbeenreportedin quarrynear Glasgow (Figure 11; Dietrich, 1%0). Gypsum canbe foundalso brecciated fermginousquartziteat theMidvaleiron mine near Vesuvius. It as awhitepowdery material that shows strong green fluorescencein long- fmsasyeUowtodanbrowncoatingsand~~~tsontheironore~heand(F waveultra-violetlight(Dietrich, 1985). Samplesof thismaterial weresubmit- or..1951). No. 1 &2 VIRGINIA MINERALS 7

KAOLINITE - KAOLINITE-SERPENTINEGROUP(hydrousalumi- rite, pinkmimline, magnetite,epidote, andchlorite(X-rayana1ysisbyR.S. num silicate). Kaoliniteisacommonalterationproductofroc Mitchell). Asarrrplefromthisl~tywasassayedandfound~m~asd feldspar content. Severalareas withinthewuntyhavenotableoc amountof silver. of hlinite. Veinsofkaolinite and halloysitearefound in fracturesin the @ Carnbrianage Antietam (Erwin)quartdteattheW.C.Mathews quqnear NaturalBridgeStation(Leomd,1x2). Kaoliiteisthechiefclay mineralin the bauxiteoccurrenceattheChalkMineRun deposit 2miles northeast of BuenaVista(Warren,andothers, 1%5). Stringersofpurekaoliniteoccurin residualclay inthevicinityof BuenaVista(Leonard, 1962). Kaolinitealso "-.- occurs as milkywhitemasses, along withmicroclime, in shearwnescutting MARCASlTE - MARCASITE GROUP (ironsulfide). Marcasiteresembles greenshaleattheLoneJackquarry(Dietrich, 1985). pyritesomewhatbutisgenerally pderincolorandhasdistinctive~~~~mb At the Irish Creek tin deposit kaolinite is foundas earthy alteration externalfeaturesas opposedto thecubiccrystalform ofpyrite. productsreplacingfeldsparandothersilicates(Glassandothers, 1958). Numeroussmall(3-10mmlengthwise)bronzeyellow striatedmarca- siterodswithacutedhmnd-shapedcross-p KIDWELLITE(hydrous sodium, iron, phosphate). Kidwelliteis foundas andcalciteincavities withinashaly part of the dolostoneat thebneJack greenishtoyellow-brownmtsandwatings withrockbridgeiteon thedumps quanynearGlasgow(Dietrich, 1%0). Somerodshavededrectangular of theDixieironminenearVeswiw(BdandZeby,1982). It occurs marcasitecrystals on theirendsresembling"hammm"(Figure 12). withstrengite,dufrenite, andrarelycacoxeniteincavities withrockbridgeite. adjacentto fibrousrockbridgeite. Dufreniteis usually foundbetween two layers of kidwellite,producing the quence~~~Mxidgeite-EdweIlited~enite-kid~eIlite(Keam~,andpenick, 1989).

LEPIDOCROCZTE(ironoxide). Lepidocrocitehasbeententativelyidenti- fiedasaconstituentofthemagneticgoethite"buttons"foundattheLoneJack quarrynearGlasgow(Di&ch, 1%3).

LEUCOXENE (titaniumoxide). Leuwxeneoccursasanalterationproduct of ilmeniteandis fairlywmmm in the greisenattheIrishCreek tin deposits (Glassandothers, 1958).

UMONI'TE(ironoxide). Linmiteisdiscreditedasa~speciesbutmay stillbeusedas a convenientfield term tobeapplied to naturaldarkbrown (II) hydrous iron oxides ofwhichexactidentitiesareunknom.Mostlimoniteis actually goethite. Limonitewasthebasis for themajorportionof Virginia's furmerironindustryandcanbefoundtosomeextentinallironmineslocated inthewunty. Itcanalsobefoundasanironstainonmanyrocbandmin&. Pseudomorphsof1imOniteafterpyriteoccureastofLexingtonnesnthe west endof South Mountain (Campbell 1881); coatingsandreplacements consistingchieflyo~te~atLod~~~Glasgow(Dietrich, 1963).

LlTHIOPHORlTE(aluminum, lithium,manganese,oxide). Blacklithiophorite constitutespartor all of someof the manganeseoxide nodulesattheKellyBankminenearvesuvius (MitchellandFreeland,1978). LithiophoriteandcryptomelanearethemostimportantmanganeseMg Figure 12Marcasite "hammer"(5 mml0ns)incalcite-linedcavitybmbne mineralsatthis deposit. JackquarrynearGlasgow;photographwurtesy of R.V. Dietrich.

MAGNETITE - SPINELGROUP(ironoxide). Magnetiteisablack,metal- MELANTERITE (hydrousiron sulfate). Melanteriteoccmsporadically as lic, strongly magneticmineral whichusually formsas sharpoctahedralcrys- greenish-white,white,crystalline,dulltopearly&gson thehostdolostone tals. Itisconsideredtobeoneof themajororesofiron. Thetitanian-richvdety attheLoneJackquanynearGlasgow(Dietrich, 1985). Themineralismost of magnetite, formerlycalled titanomagnetite,hasbeen reported from the likely analterationproductofpyrite.1tisthewmmon"alum"ofV~~and IrishCreektin deposits. It occurs as blackgrains bothin greisenandgrano- has asweet, metallic taste. diorite(Glassandothers,1958). Magnetitecanalsobefoundalong~Creek severalmilessouthwestof the tinmines. Itisassociatedwith unakite,pyrite, MICROCLINE - FELDSPAR GROUP (potassium, aluminum, siIicate). chakqyite,malachite, epi&te,miaoc~quaxQ,andchIorite@-rayanalysis Microclineiscommon inmanyof theigneousandmetamarphicrocksof the byR. S.Mitchell). BlueRidgeMountainareasinRockbridgeCounty.Itisaprimary constituent of unakite which is foundinrelativeabundanceinthevesuvius, LittleMarys MALACHITE (copper carbonate). Green malachite watings occur on Creek, Big Marys Creek, andIrish Creekareas. Microclineis thepredomi- calcite cleavage surfaces at the Lone Jack quarry near Glasgow. Other nantconstituentof sorneof thesalmonurange,finegranular, vein-likezonesin associatedminerals includedolomite,fluorite, barite, andquartz (Dietrich, afew of theshearedgreenishshalewnes withinrochattheheJackquany 1985). (Dietrich, 1985). Goodexampkscanalsobefound&ngIrishCreekappxi- Malachite alsooccurs withunakitealong Irish Creek several miles mately severalmilessouthwestofthetindepositswhereitoccursinunakiteas @ southwestof the tin mines. Assockitedmineralsare pyrite, quartz,chalwpy- deep pink toorangecleavagemasses with pyrite, chalcopyrite, malachite, 8 VIRGINIA DIVISION OF MINERAL RESOURCES Vol. 40 quartz,epidote,andmagnetite (X-ray analysesbyR.S. Mitchell). mined, insomeof itsphysicalandopticalp~es(Glassandothers,1958).

MONTMORILLONlTE- SMECTITEGROW (aluminum,magnesium, PHENAKITE (berylliumsilicate). Phenakiteis foundin greisenattheIrish silicate). ~ontmorillonitecanbe foundalong fault zones as an iteration Creek tin deposit with beryl, cassiterite, and quartz. It can also be found productof granodiorite attheIrishCreektindeposits.Itoccurs as waxlike mclosedinandinveinsthatcutchloriteandfl~orite(Koschmannandothers, 4 masses about 5 feetthick nearthe number2 workings (Koschmann and 1942). The mineraloccurs as white to brownelongatedcrystals that show others, 1942). ItisalsofoundatthehneJackquqincavit muchthe samehabitasberylandinsomecasesthey may bep cream colored coatings with calcite, dolomite and chalcopyrite (Dietrich, after beryl. Phenakitehas a higher beryllium content than beryl. It is harder 1%2). than quartzwhichitresembles. Alsophenakitecommonly showsvertical striations downthec-axis whereas they are horizontalonquartz. MUSCOVITE-MICA GROW (hydrouspotassium,aluminum, silicate). Muscoviteisacommonmtituentofmanyigneousandmetarnorphicrocks oftheBlueRidgeMoun~inR0ckbridgeCounty. Damourite is no longer amineral species but was used to describe "hy~ca"rnu~~~vitewhi&con~morew~ (Dietrich, 1990). ThisvarietyofmuscovitecanbefoundattheIrishCreektin minesassociatedwithdtaite(hnpous, 1894). Goodexamplesof finegrainedmuscoviteorsericitecan be found in greisenattheIrishCreektindeposits associatedwithcassiteriteandquartz. 'Green phengitic mica*' occurs in the quartzite and as bundles and aggregatesinstyloliticseams within thelower Erwinquartzitein Hellgate Canyon about2miles southwestof the James River at Glasgow (Lowry and DeRudder, 1966).

NACRlTE(hydr0usaluminumsilicate). Nacrite hasbeenfoundincavitiesas whitepearly microcrystallinemases,withbarite,calcite,chalcopyrite,dolomite,andmarcasiteatthehneJackquq nearGlasgow (Dietrich, 1985).

NlTER - SALTPETER OFSOMEMINERALOGISTS (potassium ni- Figure 13. Web-likepalygorskitesumundingsmapyribcrystals (-600X) trate). ~iterisfoundasdelicatecrustsandcrystallinepowderbnthewallsof fromthehne Jackquany;photographcourtesyof R.V. Dietrich. many limestonecaves. Itisalso foundin loose soils in suchcaves. Thebest knowndepositin thecounty is atNatural Bridge where Salpeter Caveis located DuringtheWarof 1812andtheCivilWarthiscavewas mined for nitratesderivedfrom niterandusedto make gunpowder.

NO~ONITE(hydr0ussodium,iron,duminum,silicate). Nontroniteisagreenish-yellow earthy tocompactmaterial withasoapy feel. It is foundassociatedwithcassiterite, quartz, beryl, fluorite, siderite, biotite, andchloriteattheIrishCreektindeposit (Koschmannandothers,1942).

ORTHOCLASE - FELDSPAR GROUP (potassium, aluminum, silicate). Orthoclaseis the primary feldspar mineral in granodioritecountryrockatthe IrishCreektindeposit(Glassandothers,1958).

PALYGORSKlTE(hy~us~ium,duminum,silicate). This raremineral occurs as soft, tough, white fibrousmasses, up to about 10 inches on cleavage planesand slickensided surfaces in the Cambrian-age Rome Formation in the Lone Jackquarry near Glasgow (Dietrich, 1960). Some of these web-like masses contain small pyrite and calcite crystals Figure 14. White, fluffly massofpalygorskitewithsmallcalcitecrystalsh (Figures 13& 14). The mineralis thought to bean alteration product of Lone Jackquarry,specimen4inches across; photographbyT. M. GathrighL dolomite. II. Palygorskitefrom this locality was firstdescribedbyLaswellandStow (1955). Theoriginal samplewassubmittedbyD.E.Brady,lr. Thisoccmence PHLOGOPITE- MICA GROUP (hydrouspotassium,magnesium, alumi- ofpalygorskiteisthefiitrecordedin Virginia. num,silicate). phlogopitemicaisgendylightbrowntoye11dwishinc01orand is foundinmagnesiumrichmetamorphicrocks andkirnberlites. Itoccursinthe PARACOQUIMBITE (iron sulfate). The mineral is found as white, fine- Mt Horeb kimberlitedeposits (Sears and Gilert, 1973). grainedsugary masses associated withcopiapiteattheKelly Bankminenear [email protected]'smtar). PIGEONITE - PYROXENEGROUP(rnagnesium,iron,calcium, silicate). Pigeonite has been found in granodioriteatIrish Creek(Koschmann and PARISlTE (fluorine-carbonateofcalciumandceriumgroup ofrareearths). others, 1942). Themineraloccursasdarkcoloredlath-shapedcrystals which Parisiteisanextremelyraremineral whichoccursrarely at theIrishCreektin arealmost identical toaugite in appearance. deposit. This is theonly reportedoccurrence for the mineral in Virginia. It formsas small elongatedbrownish-amber,transparentcrystals withberyl, PSILDMELANE. Ageneral field term for massive, hard, notspedically purple fluorite, quartz, and siderite. It rcsembles bastnasite, ameearth i&ntifiodmanganeseoxidesfoundinmostofthemines workedformanganex N0.18~2 VIRGINIA MINERALS 9 in thecounty (seewad). hasabrownish-bronzecolo~andisweakly tostronglymagnetic. Pyrrhotiteis oftenassociatedwithnickelandp&umdepo. PUMPELLYITE - PUMPELLYITEGROUP(hydrouscalcium,magnesium, rnaganese,alurninum,iron, silicate). Pumpellyiteanusasdarkgrem massesinunakitewithepidote, feldspar,andquartz. Itis usually darkergreen thanepidote. Itisfoundinan~ed~onStateHighway5615rniles eastofVesuviw(X-ray analysisbyR.S.Mitchel1).

PYRITE - PYRITE GROUP (ironsulfideknownas "fools gold''). Small pyritohedronsarefoundinblackchertnodulesinthelowerpartof thecam- brian-ageRomeFormation =the southwestern endof SallingsMountain nearNaturalBridgeStation(Leonard, 1962). Themindisalsofoundatthe LoneJackquanynearGlasgow where therelationshipoftwokindsofpyrite exists: as tarnishedrelativelycomplexcrystalssomeof which are twinned, andbrassyyellow untamishedsimplecubeswhichoccur in weblikemassesof palygmkitewithindcite-WwgsinQlostone(Dietrich,1%3a). Exce1lent~pyriteaystalsupto2in~hesinlengthcanbefound in~r~vicianlimestonein&~er's~~~~near~exin~(~~~e15). These specimensrepresentsomeofthefinestexamplesofpyrite~~sinthe Unitedstates (Figure 16; Penick, 1987). Theoctahedralcrystalsarealmost alwaysincombinationwithotherformssuchas thecubeandpyritohedron. by cube faces. Theaggregates range insize from 1 to 4 inches indiameter. Alsosomespecimens display intergrowths of two crystals that resemble twinning. Most of thepyritehascrysmedin&nsehestonematrix. Rare and complex formsofpyrite wererecogni7cdin the Lexingtonareaasearly Figure 16. ~tecrystalwithcubeandstriatedoctahedralfaces, crystal 1.3 as 1886. Limonitepseudomorphs after pyrite weredesaibedby Meem inchesacross, Bargerquany near Lexington;photographby T.M. Gathright, (1886).

Figure 15. Octahedral pyrite crystalin limestone hmBarger'squany near Figure 17. Pyritecrystal (0.8 inch) in limestone from Barger quarry near Lexington. Fieldofviewis3inck,crystalis 1.6inches. PhotographbyT. M. Lexington;photographbyD. A. Hubbard. Gathright, II. QUARTZ(si1icaoxide). Quaraisacommonrnineraloccuninginmanyrocks PYROPE -GARNETGROUP(magnesium, aluminum, silicate). Pyrbpe WithinRockbridgeCounty.Itisfoundinveinsandcavitiesinlimes~ne,aschert garnet occurs as brilliant rose-red grains in kimberlite at the Mt. ~oib massesindolos~ne,asa~ajarconstitllentinsand~tone,~uartzite,andinsome Churchareainthesouthwestern part of thecounty Pyropewas found with oftheigneousrocksintheBlueRidgeMountainpartionofthecounty.Quartz zircon, ilmenite,chTomiumrichspinel,rutile, andagreenamphibolemineaal veinsto5 feetwidearefoundwithgreisenattheIrishCreektindepsits. (Sears andGilbext, 1973). The best quartzcrystalshave beendiscovered in soils overlying Upper Ordovicianlimestone. Thesecrystalscanbefoundinmany placesinthecounty PYROLUSITE - RUTILE GROUP (manganeseoxide). Pymlusiteis the where thislimestoneoccurs. The crystals weather from cavitiesin the lirne- mindthatiscommonlyd~c~ys~ore"byminers. Itoccursatmost stone. Erosionscarsbetweenhestoneou~sarethebestp~tolookfor of thernanganesedeposits in Virginiaasbothsteelgray crystals andasblack crystals. Crystals up to 4 inches in length have been found by the writer near sootyreniformrnasses. Pyrolwiteisalsofoundasdarkbluishgrayden~tes Collierstown. Several farms in the area haveproducedexcellent crystals. onquartziteatthehneJackquamy near Glasgow (Dietrich, 1%3a). Thesecrystalsrange fiomclear tosmoky. Some haveillite(clay)inc1usions which can produce spectacular specimens (Figure 18). Both scepter and PYRRHOTITE(ironsulfi&). F'yrrhotiteisreportedEromtheIrishCreektin reversesceptercrystals to 3inchescan be found, somearedoubly terminated, deposit(M.H. Stow,personalcommunicationtoR.V. Dietrich). Themineral andmosthaveextremelysmoothand lustrous crystal faces. Crystalsmayalso 10 VIRGINIA DIVISION OF MINERAL RESOURCES Vol. 40 becornp1exandshowa"stacked"arrangment. Someof thesecrystals have masses but crystals as muchas 6 mm across occur withcassiteritecrystals beenusedinjewelryp&ularly theclear oneswhichresemble the famous (Glass andothen, 1958). Themindshowsbrightblue fluorescenceunder "herkimerdiarnonds"of New Yakstate. Goodcrystalscanalsobe foundin ulmvioktlight theKerrsCreekandHouseMountain meas. Interesting single crystalsand 4 crystal clustershave alsobeenfoundin Barger's quamy. ~rnethyst,thepurplevarietyofqu~artZhasbeenf~undatthe~h~reek tindeposits,althoughnotof gemquality(Zeitna,1%8). Gemqualityjasper (quartz coloredred by iron oxide) has been foundin the AmoldValley area (HerbatGrow, personal communication).

Figure18. Two3inch lmgquartzcrystalshmnearCoIlierstown,crystalon kftis~ubl~~andhasck~&1~~~~hoto~hb~~.~.Gz&ight, 11. Figure 19. SpechensofrockbridgeitehmtheDixieminewithtwopolished cabochnscuthmthesamernaterial,cabwhonsare 1 inch1ong;photograph RHOMBOCLASE(hydrogen,ironsulfate).Rhomboclaseis foundas white by T. M. Gathright,ZI. subtranslucentsugary masses atop copiapiteat theKelly Bank minenear Vesuvius (RS.Mitchell's notes). SCORODITE(hydrous iron arsenate). Scorodite is analterationproductof arsenopyritein greisen and in quartz veins at the Irish Creek tin deposit RoCKsRIDG~(hyhusirosmangane~phosphate). (Morgan, 1938). Itoccursasleekgreenen~~~stationsonarsenopyrite. Rockbridgeiteis arelativelyrare mineral named for RockbridgeCounty. Virginiabecauseitwasfirstrecognizedin thiscounty as adistinctmineral SERPENTINE- KAOLINITE-SERPENI'INEGROUP (hydrous magne ~esinsamples~mtheMidvdeironmine~~uthofVesuvi~~.Themineral sium, iron, silicate). Serpentine has beenidentifiedinsamplesfrom theMt was found in some abundance on the dumps of the mine. The name Horebkimberlitedeposits(X-ray analysesby Ol. mkbridgeitewas proposedby bfessor CliffordFroradellofHarvarduni- versityformaterialpreviouslyiden~dasdufrenite~ron&ll,1949). The SIDERITE - CALCITE GROUP (iron carbonate). Sideriteis the most Midvdeminehasbeenrw1aimedandnoevidenceofminingremains. abundant carbonateat theIrish Creek tin deposit. It occurs inveins and in Morerecentlyrockbridgeite can be found on the dumps of the Dixie brownrhombohedral masses both inthegreisenandveinquartz. In hand rnineeastofvesuuius@mvoodandZelamny, 1982). Themineralomas specimen siderite superficiallyresembles cassiterite however sideritehas darkgreen,fine-grainedmassesandasdark~eenfibmusconcentricbands ~~m~mboh~cl&va~ewhile@teritedoesnotn~mineralis with reddishbrown toblackgoethite. Well forrnedcrystalsofmkbridgeite associatedwithankerite, fluorite,andcassiterite(Glassandothas, 1958). havenotbeen reported Other datedrnineralsarecacoxenite, dufrenite, kidwellite, andstrengite(Keamsandpenick, 1989). It hasbeendiscovered recently that rockbridgeite from the Dixie mine takes an excellentpolish whichresembles black jade. Polishedcabochonscanbe usedwith sterling silver tomakeattractivejewelry(Figure 19).

ROZENITE -ROZENITEGROUP(hydrousironsulfate). Rozenitecanbe foundwithmelanteriteasdull whiteen~~stationsondolostoneattheLone Jackquarry nearGlasgow(Dietrich, 1963).

RWU-RUTILEGROUP(titanium0xide). Redgrajnsofrutilearefound with blackilmenitecreatingabandedappmmcein quartziteat the base of theRecambrianUni~~iF~onontheRobinsonGaproad,2mileseastof BuenaVisita(B1oomerandDeWig 1941). Rutileisalsofoundinthecoun~ rockandthegreisenat theIrish Creek tin deposit (Glass andothers, 1958). RutilegTains havebeenreptedfrom thekimberlitedepositsnearMt. Horeb Church(SearsandGilw 1973).

SCHEELITE(calcium tungstate). Scheelite is animportantoreof tungsten andoccursboth in greisenandincarbonateveinswith wolframiteandcassi- teriteat the Irish Creek tin deposits. It mainly appears as brown cleavage VIRGINIA 1

Glasgow (Die.1985). clay from the Kelly Bank mine near Vesuvius are included on the list of ~hsintheNationalStudyCoW0nofMkak"intheSmifhonh STRENGm(hydrousironphosphate).Strengiteoccursasminutereddkh Institution(Dietrich, 1990). browncrystalsinfmctms, lmilemuhcartofMidvale(Koening,1877). Also brightpurplecrystalsof strengiteonbothmkbridgeiteandkidwellitewere reportedfromtheMidvalemine(BarwoodandZelany, 1982). Strengiteis relatively common at the Dixie mine andoccursas divergent sprays and sphericalaggregatesofbrilliantlilac-pinkp. Thecrystalsaregenerdy less than3 mm in sizeandusuallyform in cavities with kidwellite. Small flattenedcrystalsofstrengitehavealsobcenobservedasradiatingaggregates on goethiteorrockbridgeite(Kearm and Penick, 1989).

Tm(magnesium,alumimum, beryllium, oxide). Theraremineral taaffeitecanbefoundasbrightgreen~gsonca~~iteriteattheIrishC& tinmines(R.S. Mitchell'snotes). This is the only reportedoccurrenceof taaffeiteinvirginia.

THENARDITE (sodium sulfate). Thenadte,thatfluarescesbrightlightblue Figure20. Blacktourmalinec~ystalsinclearquartzfromtheErwinquartzite in long-waveultra-violetradiation, was founfromtheLone Jackquarry, specimen3inches 1ong;photographbyT.M. dolostonein the LoneJackquarrynearGlasgow (Dietrich, 1985). GathIight,II.

TAL,C(hydrous~umsilicate).Talc,analterationpmhctof~the, WAVELIlTE(hydrousaluminumphosphate). Wavelliteisthemostabun- wasidentified attheMt HorebChurchkimberlite&posit~ 0.M. Fordham). to 7 mm in diameter (Mitchelland Freeland, 1978). Wavellite occurs as TOURMALWEGROUP(complex hydrous silicateof turquoiseandotherphosphatemineraIs(Figure21). TOUUvM.DE - ~ nodulesassociatedwith - sodium,magnesium, aluminum,and boron). Blacktourmalinecrystals,probablyschorl, have been foundinaquartzvein intruding quartzite in the Erwin Formation at the Lone Jack quarry near Gksgow(Figure2Q JLDickinson,Jr.,e comm~n,1980). Small blacktourmalinecrystalshavealsobeenreportedfrom thetindepositsnear IrishCreek, where they generally occur in fracturesincassiterite(Glassand

TURQUOISE -TURQUOISEGROUP (hydrouscopper,aluminum,phos- ph*) Turquoisehasbeenidentifiedfrom thedumpsoXellyBankironmga- nese mine near Vesuvius. Itranges from green to blue-green to whiteand occurs as earthy porousmasses2 to 3mm across. Themineralalso occurs as thinbotryoidalcrusts which exhibit color banding (Mitchell andFreeland, 1978). Tquoiseisalso foundhnoduleswithwavellite. Whenbrokenopen thesenodules oftenrevealwater-clear prisms of wavellite onmassivetur- quoise. They makeexce11entspecirnens (BarwoodandZelazny,1982). No gem qualityturquoise has been foundatthislocality.

VARI~(hydrousalminumph0sphate).V*iteis foundattheKelly Figure21. ThreeinchnoduleofwavelliteandturquoisefromtheKelly Bank BankminenearVesuViuswithwavelliteandturquoise.Itoccursasthinwhite mine; photograph by HowardFreeland. to gray vitreous crystallinecrustswithbotryoidal andglobular structures. Thesecrusts are fibrous to granular and havesurfaces which sparkledue to WOLFRAm(mn, manganese,tungstate).Wolframiteisinkndbtein small crystal faces (MitchellandFreeland, 1978). Variscitealsooccursas compositionbetween ferric iron-richferberiteand manganian-richhubnerite. It occurs as blackveinletsin greisen with cassiterite andmuscovite. It also forms~aealongmicacleavageplanes~cinganintricatemeshwork. which towards thecenter of themeshwork, may form an almost solidmass VERMICULITE (hydrousmagnesium, iron, silicate). Vermiculiteis ayel- (Glassandothers, 1958). Wolfhmiteisalsocloselyawx%tedwithscheelite. lowish-brownmicaceousmineral foundasanetworkof veinlets andlocal aggregates in greisen at theIrish Creek tin mines. Itresembles biotiteand ZIRCON (zirconiumsilicate). Zircon has been reported from Petetes Gap nontroniteandisassociatedwiththem(Koschmannandothers, 1942). (Dana, 1892). It isalso foundatthelrishCreektindepositsassmallelongated tetragonalcrystalsingrandioriteandasarelictmineralinthegreisen. Itmay WAD(softmanganeseoxi&). Wadis nolongera~~editedmhed~esbutalsooccurinclusters (Glassandothers, 1958). Atleastfourmorphologically distinctpopulationsofzircons havebeenrepoaedfromthe Mt HorebChurch kimber~~deposits(sears and~ilbert,19%). ofwadareasthey wereoriginallyreported. Wad war reported from Hogpen Hollow and the Midvale mines near ZOIS~-~GROUP(hydrous01cium,aluminu~siliofe).Zoisite i?) Vesuvius (HeweaandFleischer,1960). Psilomelanepseudcnmorphsaftex can be foundat theIrish Creek tin deposits where it occurs as prismatic aystalshcalcitevein~with~lin0misite(G1,I958). VIRGINIA DIVISION OF MINERAL RESOURCES Vol. 40

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Kearns. LE., andPenick, D. A, 1989,TheDixiemine,RockbridgeCounty, Zeimer,J.C., 1968,Appalachian MineralandCkmTrails: LapidaryJoumal Virgink RocksandMinerals.~.64,n. 1.p.42-45. h.,Devan,Pemsy~vania, 134p.

Koenig, G. A., 1877,0nstrengitefromRockbridgeCounty,Virginia: Acad- emy of NationalScience+Philade1phiaFbcadhgs.p. 227-278. _ N0.18~2 VIRGJNIA MINERALS

List of Minerals from Rockbridge County, Virginia 61. Muscovite(micagroup) 62. Nacrite 63. Niter 64. Nontronite 65. Ortlmlase(fe1dspargroup) 3. Anatase 66. Mygmkite 4. Ankerite(do1omitegroup) 67. Parisite 5. Aragonite(arag0nitegroup) 68. Phenakite 6. Arsenopyrite 69. Phlogopite(micagroup) 7. Augite(pyr0xenegroup) 70. Rgeonite(pyr0xenegroup) 8. Barite (barite group) 71. Psilomehe 9. Beryl 72. Pumpellyite(pumpellyitegr0up) 10. Biotite(micagroup) 73. (pyri~group) 11. Bisite 74. Wpe(gametgroup) 12 Biitite 75. pyrOlusite(rutilegroup) 13. Cacoxenite 76. Pyrrhotite 14. Calcite (calcitegroup) 77. Quartz 15. Cassiterite(rutilegr0up) 78. Rhomboclase 16. Celadonite(micagroup) 79. Rockbridgeite 17. Chalcopyrite(chalcopyritegroup) 80. Rozenite (rozenitegroup) 18. Chlorite(ch1oritegroup) 81. Rutile(rutilegroup) 19. Churchite 82. Scheelite a. Claudetite 83. Scorodite 21. Clinowisite(epidotegroup) 84. Serpentine(ka0linite-qntinegroup) 22. cqkpite 85. Siderite(calcitegroup) 23. Cryptomelane(cryptome1anegroup) 86. Silver (element) 24. Diapsi&(pyroxenegroup) 87. Sphalerite(sphaleritegr0up) 25. Dolomite(do1omitegroup) 88. Spinel(spine1group) 26. Dufmlite 89. Starkeyite(rozenite group) 27. ~~idote(e$otegrou~) 90. Strengite 28. Epsomite 91. Taaffeite 29. Feldspar group (seemicroclineandorthoclase) 92. Tak 30. Fernhornblende(amphibole group) 93. Thenardite 31. FLnite 94. Tourmaline(tommahegroup) n n~~~apatite(apatitegro~p) 33. Galena 34. Calenobismutite 97. Vermiculite 35. Garnet (garnet group) 98. Wad 36. Gibbsite 99. WaveIlite 37. coethite 10. wolflamite 38. Gold(e1ement) 101. Zircon 39. Craphite(e1ement) 10L Zoisite(epid0tegroup) 40. Gypsum 41. Halloysite(ka0linite--tinegroup) 42 Hematite (hematitegroup) 43. Hexahydrite 44. Hypersthene(pyroxene group) 45. lllite 46. Ilm&(ilmenitegroup) 47. Jarosite(alunitegroup) 48. Kaolinite(koaljnite-qntinegroup) 49. KidweIlite so. kpi- 51. Leucoxene 52 LimDnire 53. Lithiophorite 54. Magnetite(spine1group) 55. Malachite 56. Manganite 57. Marcasite(marcasitegroup) 58. Melanterite 59. Microcline(fe1~group) M Montrndonite(mectitegroup) VIRGINIA DIVISION OF MINERAL RESOURCES

COUNTY TOPOGRAPHIC MAPS

Since the early 1970s theDivision of Mineral Resources,incooperation with theU.S. Geological Survey Topographic Branch, has been producing 1:50,000 scale county topographic maps. Cities are incorporated with their adjacent county, for example the City of Fredericksburg is included with SpotsylvaniaCounty. The followingcounties andcities, shown onthemap below havebeencompleted. Currently BedfordandRmkbridgeCountiesare. Additional counties are planned as funding allows. Anindex to the topographicmaps inVirginia is availablefree fromtheDivision of Mineral Resources (DMR). County topographic mapscost $4.00plus4.5% sales tax (Virginiaaddressesonly) plus shipping. Contact DMRat P.O. Box 3667, Charlottesville, VA 22903 or by telephone - 8041293-5 121for postage charges. Prepayment is required.

El Printed

County Topographic Maps

GEOLOGIC MAPS I

Geologicmapping has been an ongoing activity by the Division of Mineral Resources and its predecessors since 1835. The modem era of geologic mapping began in the late 1930s when the topographic base maps were prepared using aerial photographs. A geologic map is agraphicrepresentationofm. They provide information about the age, composition,occurrence of folds and faults, mineral deposits and geologic factors that impact man's activities. Geologicmapsare prepared from field surveys and remote sensed data, such as geophysical surveys. The geologicmap is the principal sourceof geological informationneededfor theresolutionof nearly all basic and applied earth-science research and decision-making concerns, and is aguide tomost human interactionswith the earth. Examples are: distributionandavailabilityof energy andmineralresources; locationandnatureofnaturalhazards; distributionof waterresources; basic datafor planning consuuction projects, such as dams, highways, and pipelines andindustrial plants. Benefits of using geologic dataderivedfromgeologi~mapsinclude: mitigationof natural hazards; location of karst areas andmines and quarries; groundwater protection; planning for urban growth, mineral extraction, and sequential land use. Fourteen counties (scale - 1:50,000,1:62,550, or 1: 100,000) have geological maps. Nine 15-minute (scale - 1:62,500) quadrangles and one hundred andninety-four7.5-minute(scale - 1:24,000) quadrangles have beenpublished. The following three index maps show the location of geologic maps at a scale of 1:62,50Oand larger. Additional regional maps are availablebut are not shown on the maps. A free "List of Publications and Maps" is available from the Division of Mineral Resources. N0.182 VIRGINIA MINERALS

7.5-MINUTE QUADRANGLE GEOLOGIC MAPS (1 :24,000)

Published by DMR

Published by USGS

15-MINUTE QUADRANGLE GEOLOGIC MAPS (1 :62,500 SCALE) Postmaster: Virginia Minerals Send address corrections to: Second-Classpostage paid at VirginiaDivision of Mineral Resources Charlottesville, virgin& P. 0.Box 3667 ISSN 0042-6652 Charlottesville, VA 22903

COUNTY GEOLOGIC MAPS