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Home , Beudantite, Bromargyrite, Calaverite, Carminite, Conichalcite, Emmonsite

formed material (toward the interior of the rock cavity) is more cloudy. The chalcedony fluo- resces bright green under short-wave UV light, typical of hydrous silica containing trace amounts of the uranyl (UO2r*) ion. The last- NewMexico Symposium formed layers of chalcedony tend to be the most brightly fluorescent, but some of the earliest- formed layers (adjacent to the host rhyolite) The Sixteenth Annual New Mexico also fluoresce brightly. The most cloudy/milky Mineral Symposium was held November chalcedony usually shows little . II and12,7995, at New Mexico Institute of Fluorescent banding in the layers helps to trace Mining and Technology, Socorro. Following growth patterns in the chalcedony. are abstracts from talks given at the s)./mpo- Cross-sectioning reveals that the early- sium that concern New Mexico. The num- formed chalcedony in the interior of the nod- bers in parentheses refer to locations on the ules has grown radially from nucleation sites on map' the rock cavity walls, but later chalcedony growth appears to have progressed outward toward the cavity opening, parallel to the cavi- ty walls. Thin, green-fluorescent chalcedony- MrNsnels AND MINING HISToRy oF THE filled fractures in the surrounding rhyolite Flsnno-He.lrovER DrsrRrcr, GneNr CouNrv, appear to mark pathways by which silica-bear- Nrw Mrxco, by Robert W. Eueleth, New ing water was carried into the cavities. Toward Mexico Bureau of Mines and Mineral the interior of the cavities, some of the last- Resources, Socorro, NM 87801-4796 (1) The origin of agate and chalcedony noduies formed fibrous chalcedony grades into a layer has always been something of an enigma to composed of minute, euhedral drusy qtartz, The Fierro-Hanover minins district in Grant mineralogists, as well as to the general public. with about 0.5 mm in diameter. Also in County, southwestern New Merico, is one of Although the general concept of their formation places, the outermost layer of chalcedony and the state's more productive mining areas, hav- has been fairly well understood, the precise drusy is overlain by a surface coating of ing seen nearly continuous production of base details involved in the processof their forma- -stained, fibrous, length-slow chalcedony(?) ,precious metals,and iron for more than tion at each particular locality have tended to be about 0.5 mm thick. Recent studies have shown a century. more difficult to explain. that much length-siow chalcedony contains The entire district is contained within the A particularly intriguing occurrence of chal- moganite (also known in the literature as roughly trianguiar-shaped features known as cedony nodules has recently been recognized in lucetite). which is a monoclinic SiO, polymorph the Santa Rita horst, which is sharplv bounded mid-Tertiary silicic volcanic rocks near the distinct from quartz (Heaney and Post, L992); on the northwest by the Barringer'fiult, on ihe -New Mexico border in southwestern XRD confirmation for the presence of moganite northeast by the Mimbres fault, and less dis- Hidalgo County, New Mexico, and adjacent in the Hidalgo County chalcedony has not yet tinctly on the south by the Groundhog and Cochise County, Arizona. The occurrence is in been obtained. In some nodules, small patches Nancy faults. The intruslon of the Fier- the vicinity of Clanton Draw and Geronimo of glassy. blebby opal (optically isotropit) with ro-Hanover granodiorite stock uplifted and Pass, in the Coronado National Forest. The nod- a very bright green fluorescence were the last fractured the sedimentary rocks in the district. ules formed within a late Oligocene, high-silica material deoosited. These fractures provided channels through rhyolite lava flow (Rhyolite of Clanton Draw) The origins of agate, chaicedony, and geodes which the mineralizinq solutions invaded the along the north margin of the Geronimo Trail have been the subiect of increased interest and and formed the extensive contact- cauldron (Mclntyre, 1988; Erb, 1979; and study in recent years. A major controversy, not metamorphic and skarn deposits in the Combi- Charles Bryan, personal communication, 7995). yet resolved, has been whether chalcedony nation, Princess, Kearney, Empire, and Pewabic The chalcedony nodules were recently forms by precipitation from dilute aqueous mines in the southern and central parts of the noticed by Charles Bryan (University of New solutions that flow through cavities, or by crys- district and the Union Hill irotr depositsand the Mexico) in the course of field work. Ramon S. tallization of a dense, viscous silica gel that fills Continental mine at Fierro in the northern r:art. DeMark and Brian lluntsman learned about the a cavity as a closed system. Building on the These and other smaller mines have pro- occurrence from Bryan. The noduies range in speculations and observations contained in duced a total of more than a billion pounds size from about an inch to l0-12 inchesin diam- such classic publications as those by Liesegang each of and zinc, 50 mitiion pounds of eter. They are typically hollow, and only par- (1910) and Ross (1941),some very good treatis- , 5 million ounces of , and 50,000 tially fill somewhat angular, irregular-shaped es on the subject have appeared within the past ounces of . The district is the state's leading cavities in the host rhyolite. The chalcedony lin- dozen years; for example, Landmesser (1984), producer of iron totalling some 8rz million ing making up the nodules is typically from 0.5 Macpherson (1989), and Pabian and Zarins short tons. Concurrent with ihe production has to 1 cm thick. Some nodules are flattened or (1994). In addition, an increasing number of come a long and colorful mining history begin- elongated parallel to the direction of flow band- papers have applied modem techniques of ning in ca 1858 with German metallurgist Sofio ing in the rhyolite; others are subspherical. mineralogy and geochemistry to the study of Hinckle at the old Hanover mine neaipresent- Most nodules are found loose,as "float" pieces, agate and chalcedony; for example, Fallick and day Fierro.The richestcopper ,some grad- usually still partially attached to pieces of the others (1985); Graetsch and others (1985); Wang ing 58% Cu, were produced here until the Civil host rhyoljte. and Merino (1990); Heaney (1993); and Lueth War. A few occur as loose nodules totallv free of and Goodell (in prep.). The Hanover and other mines have produced rhyolite matrix, and some are r""r-r e-b"dd"d Symposium participants are invited to share an abundance of col.lectiblemineril species in rhyolite boulders or outcrops. An unusual their own ideas and insights about the origin of including quartz. , , , feature of the nodules is the way the chal- agate and chalcedony in the discussion follow- native copper, and turquoise, as well as wide cedony appears to have "oozed" out of the inte- ing this presentation, so that together we may variety of copper oxides and sulphides. Excei- rior surface of the cavity in rhyolite; lobes of try to reach some increased level of under- lent specimensare still produced occasionally chalcedony surround, but usually do not com- standing of what these nodules are telling us at the currently active Continental mine, the pletely close off, the opening of the host cavity. about the deposition of silica within cavities in Union Hill iron pits, and until recently, the Rarely, completely closed, hollow noduies have rhyolite. I would like to particularly acknowl- mines along the Barringer fault north of Fierro. weathered out of the rhyolite; some such nod- edge the advice and unpublished information ules have thin enough walls and contain a large provided by Charles Bryan, Ramon S. DeMark, enough void to float on water. and Virgil E. Lueth in preparing this paper. The chalcedony is fibrous with a radiating OzucrN op cHALCEDoNy NoDULES rN RHyoLITE microstructure. Fibers are length-fast (elongat- References FROM THE PELONCILLOMOUXTAWS, HTOETCO ed perpendicular to the c-axis), as has been Erb, E. E.,1r.,1979,Petrologic and structural evolution CouNrv, Nrw Mrxrco, by Peter Modreski, l. reported to be the case for most agate and chal- of ash-flow tuff cauldronsmd noncauldron-related U.S. Geological Survey, MS 905, Box 25046, cedony. The color ranges from pale pink to volcanic rocks in the Animas and southern Federal Center, Denver, CO 80225-0046 (2) milky-white to colorless; typically, the later- PeloncilloMountains, Hidalgo Comty, New Mexico:

February 1996 New Mexico Geology quartz Unpublished Ph.D. thesis, University of New related, main - monzonite intrusive vidual,0.5 mm, olive-green crystals perched on Mexico, Albuquerque NM,287 pp. (Williams, 1978). crusts of . Aurichalcite and rosasite Fallick, A. E., Jocelyn, J., Donnelly, T., Guy, M., md The main workings consist of several shafts [(Cu,Zn)r(CO)(OH)r] are both found in attrac- Behm, C., 1985, Origin of agates in volcmic rocks and a number of adits, all of which were appar- tive specimens in a number of areas throughout from Scotland: Nature, v 313, pp. 672474. ently interconnected at one time. Workings that the mines, always in association with coiorless, Graetsch, H., Florke, O. W., and Miehe, G., 1985, The are currently accessible form a Byzantine series bladed, hemimorphite [ZnoSirOr(OH)rHrOl nature of water in chalcedonv and opal-C from crystals. was found in a single speci- Brazilian agate geodes: Physici and Chemistry of of drifts, declines, stopes, and "dog holes," , v. 12, pp. 300-306. Mining by "following the ore" is probably men on the dump of an adit high on the north- west side of the Granite Gap hill. This adit and Heaney, P J., 7993, A proposed mechanism for the responsible for this extreme irregularity of growth of chalcedony: Contributions to Mineralogy openings and suggests that the ore shoots dump were the source of the greatest volume and Petrology, v 71.5,pp. 66-74. themselves were highly irregular although they and variety of . [FeS2l oxidized Heaney, P J., and Post, J. E.,7992,Thewidespread dis- were always near the intrusive dikes. to [FeO(OH)] is common on this tribution of a novel silica polymorph in microcrys- was detected early and was attrib- dump, and blue botryoidal hemimorphite can ,14 talline quartz varieties: Science,v. 255, pp. l-443. uted to oxidi./ed -group minerals be found as well. Plattnerite [PbOr] associated Landmesser, M,1984, Das Problem der Achatgenese; Fe)rr(Sb,As)rS1aJ (Lindgren et aI., 1910) with white and brown is Mitteilungen der Pollichia, v. 72, pp. 5-137. Bad [(Cu, although no relict tetrahedrite has been found. found in this adit in a small area with difficult Diirkheim, Poliichia-Museum. Williams (1978) reported a number of access. Willemite in colorless, hexagonal prisms Liesegang, R. E., 1910, The origin of agate: Zentralblatt and botryoidal, gray fiir Mineralogle, 593 pp. minerals but did not provide specifics of occur- [Zn(CO3)l along with two single crystals of Lueth, V W, and Goodell, P C., (in prep.), Fluid inclu- rence, associations, and physical descriptions were found on the dump of sion study of geodes from Rio Grande do Sul, for most of them. He did, however. note the lCu.(CO.)r(OH)21 Brazil: implications for the genesis of geodes: ubiquitous presence of in unctu- the hish;,st adit-on ihe southwest side of the unpublished manuscript. ous phlogopite surrounding the other sulfides. hill. Macpherson, H. G., 1989, Agates: London, British This material was not detected during this As the only known New Mexico location for Museum (Natural History),72 pp. investigation. Williams (1978) determined that carminite and one of a very few arsenate loca- Mclntyre, D. H., 1988, Volcmic geology in parts of the the silver in the ore was originally derived ftom tions in New Mexico, Granite Gap has added southem Peloncillo Mountains, Arizona md New the of matildite [AgBiS2l embedded in the . one more interesting chapter to story Mexico: U.S. Geological Survey, Bulletin 1671, L8 Granite Cao is relativelv unknown to mineral New Mexico minerals although the story is by Pp. collectors witil the exceDtion of a small cadre of no means complete. Pabian, R. K., and Zarins, Andrejs, 1994, Banded agates, origins and inclusions: University of micromineral enthusiasts. This is probably due References Nebraska-Lincoln, Educational Circular No. 12, 32 to the remoteness of the area plus the paucity of pP. hand-sized specimens. However, it is now Gillerman, Elliot, 1958, Geology of the central Ross,C. S., 1941,Origin and geometric form of chal- revealed to have a siqnificant suite of attractive Peloncillo Mountains, Hidalgo County, New cedony-filled spherulites from Oregon: American secondary arsenate minerals plus a number of Mexico, and CochiseCounty, Arizona: New Mexico Mineralogist, v. 26, pp. 72I-737. additional snecies o{ interest to mineral collec- Bureau of Mines and Mineral Resources,Bulletin Wmg, Yifeng, and Merino, Enrique, 1990,Self-organi- tors. Arsenate species found during this study, 5/, rJlD. zational origin of agates:banding, fiber twisting, in order of abundance, are mimetite [Pbs Lindgren. Waldemar, Graton, Louis C., md Gordor! compositiory and dynamic crystallization model: (AsOfrCll, conichalcite [CaCu(AsOf(OH)J, Charles, II, 1910, The ore deposits of New Mexico: Geochimica et CosmochimicaActa, v 54, pp. Paper beudantite [PbFe"3*(AsO)(SO)(OH)61, agard- U.S. Geological Suwey, Professional 68. 1.627-1638. Williams, S. A.,7978, Mineralization at Granite Gap, ite-(Y) [(!Ca)Cuu(AsO/3(oH)63H2o] (Wil- County, New Mexico: New Mexico Iiams, 1978, identified the related species mix- Hidalgo Geological Society, Guidebook 29, pp. 329130. ite), (cuprian) [(Zn Cu)r(AsO/(OH)J, Carurturrn AND orHER ARSENATESFRoM GRANITE and carminite [Cur(AsOr)(OH)], * Part of this work was performed at Sandia Gal, Hnelco CouNry NEW MEXrco*, by (AsO;XoFI)r]. Species identification [(PbFe23* National Laboratories, operated for the U.S. Ramon S- DeMark, 530 East Arch St., was accomplished by physical characteristics Department of Energy under contract number Marquette, MI 49855; ar.d Paul F. Hlazta, and electron microprobe analysis. DE-AC04-94AL85000. Department 7822, MS-1405, Sandia National Mimetite color and habit are quite variable. Laboratories, Albuquerque, NM 87185-1405 Crystals may be bright canary yellow or com- (3) pletely white, and the habit varies from 1 mm spheres to hexagonal prisms that may termi- MnlEnelocv oF THE TODILTo URANIL\4 DEPoSITS, Granite Gap is in the central Peloncillo nate with the r:inacoid or b(anch into "wheat Gneurs DrsrRrcr, Nrw Muxrco, by William R. Mountains neir the "boot heel" of southwest- sheaves." Conichalcite is typically grass green Berglof, University of Maryland, Asian ern New Mexico and was one of the major pro- and may be individual spheres or mats and Division, Unit 5060 Box 0100, AOP AP 96328- ducers of the San Simon mining district. It can crusts of intergrown sheaves. Coverage of some 0100; and Virginin T. McLemore, New Mexico be reachedby traveting west oi l-10 for 16 mi specimens exceeds several square centimeters. Bureau of Mines and Mineral Resources, past Lordsburg to Road Forks then south on Beudantite is found in verv smali (less than 0.1 Socorro, NM 87801-4796 (4) U.S. 80 for approximately 11 mi. The mining mm) crystals that are yellow green to brown area is on a hill southeast of the highway and is and subtranslucent. Agardite-(Y) occurs in minerals in the Grants district were about one quarter of a mile from the highway. greenish-blue, acicular sptays with individual first discovered in the late 1940s in the Todilto Most of the area is in private ownership as crystals to 0.5 rnm. Some crystals are extremely , which has yielded about 2oh oI the patented claims. fine whereas others are sufficiently coarse to total uranium production from the district. The Mining exploration at Granite Gap began recognize the hexagonal symmetry. It is found first uranium minerals discovered and mined about 1880, and there was a great deal of activ- with conichalcite and adamite but is difficult to were brightly colored yellow minerals. ity at the site in 1904 when it was visited by distinguish from the ubiquitous aurichalcite Significant quantities of "black ore" containing Lindgren, Graton, and Gordon (1910, p. 330). [(Zn,Cu)u (CO3)2(OH)6]. Adamite was deter- uraninite (pitchblende) and were dis- Extensive production stopped around 1915 mined to be cuprian by electron microprobe covered as mining progressed, sometimes asso- although small amounts of ore were shipped analysis. Individual, bluish-green, equant crys- ciated with blue-black oxide miner- until at least 1926 and probably much later as tals about 0.2 mm across are translucent with als, and it became evident that the yellow min- reported by Gillerman (1958, p. 101). The mines white patches. Olivenite was determined to be erals formed by secondary near-surface oxida- were operated for lead and silver with some zlnciai, and the crystals are 0.2 to 0.3 mm and tion of the black ores. Yellow minerals are rare minor amounts of gold. The ore occurs in equant. They are lustrous, transparent, and sea- or absent in the deeper mines. Lead-uranium hydrothermal veins in Mississippian limestones blue green. Carminite occurs as bright, isotopic dating of uianinite indicates that it near or adjacent to Tertiary dikes of a light-col- carmine-red soravs less than 0.2 mm across and formed shortly after the limestone was deposit- ored, fine-grained, quartz monzonite porphyry as drusy cruits'with very finely crystalline ed; the yellow minerals formed at various later (Williams, 1978). No contact metamorphic "blebs" of yellow-green beudantite. A copper flmes. effects were observed in the limestones adjaient arsenate, as yet to be identified, was found as , barite, and pyrite are the most com- to the dikes (Gillermary 1958; Williams, 1978) 0.1 mm purple-red octahedra and remains mon accessory minerais in and near the urani- although an extensive contact metamorphic under study. um ore. Fluorite occurs in small crystals and aureole does occur around the later, genetically Bromargyrite [AgBr] is usually found as indi- fine-grained irreguiar replacements; known

New MexicoGeology February 1996 79 occurrences are roughly coextensive with ura- '4HrO; hewettite, CaVoOro.9HrO; metahewettite, least 43 Te-bearing districts, 24 reported tel- nium minerals and are probably not related to CaV.OI o.3H2O; santaf?i te", ( N.An,Fe,A l,Mg)8Mn8_ luride minerals, and tellurides with more var- fluorite vein deposits in the nearby Zuni dis- (Ca,Sr,Na),,, (VOr16(OH,O)ro 8HrO; grantsite, ied chemical elements than other areas in this trict. Uraninite occurs in disseminations and NarCaV, O32 .8H2O; goldmanite, Car(V,Fe,Al)2 study. On the other hand, has the least replacements along bedding or irregularly si3o12. number of verified minerals, hence the throughout mineralized limestone, and occa- least diversity in chemistry. sionally along fractures. Where uraninite is The tellurides present in the four-corner abundant, the limestone may appear red from states are representative of many worldwide associated fine-grained . Microscopic TELLURIDEoCCURRENCES IN THE FOUR-CoRNER hvdrothermal svstems with low to moderate galena crystals are associated with high-grade SrArES, U.S.A., by Bruce Geller, Advanced temperatures of formation. Tellurides were uraninite; much of the lead in the galena may Geologic Services, 700 Vista Lane, deposited late in the paragenetic sequence of have been derived from decay of uranium. A Lakewood, CO 80215 mineralization and are associated with certain few deposits extend into the Entrada Mesozoic/Cenozoic -bearing intrusions, , immediately below the Todilto, with (abbreviated Te) is one of the rarest in many cases Cu and/ot Mo alkalic porphyry uraninite filling pore spaces between sand elements for.rnd in the earth's crust, with an systems. Tellurides are found either in the por- grains. The blue-black vanadium minerals are average abundance far lower than platinum's. phyries, limestone replacements, skarns, or mainly hiiggite and paramontroseite and often Though rare, telluride minerals (those bearing most commonlv in epithermal veins. An entire- occur in fractures associated with coarse calcite. teliurium) are noted in all 13 mining states in ly different origin is illustrated by the Vulcan The most common yellow mineral in oxidized the western U.S., including the four-corner deposit near Cunnison, Colorado, which is a uranium-vanadium ore is tyuyamunite, the ca1- states of Arizona, Colorado, New Mexico, and submarine exhalative massive-sulfide deposit cium analog of , which forms in the Utah. For the remainder of this discussion, the of Proterozoic age. high- limestone environment. It is term telluride minerals will be restricted to Most of the telluride occurrences in the west- abundant in thin but conspicuous coatings on unoxidized species, excluding tellurites and tel- ern U.S. do not occur in distinct belts. Telluride fractures and bedding surfaces in the limestone, lUIates. occurrences in Arizona are confined to the far and occasionally as platy crystals or in pulveru- Curiousiy, certain areas are broadly enriched southeast corner of the state except for the Tiger lent masses. Tyuyamunite occurs along with the in telluride minerals such as Colorado, whereas district near the state's center. Colorado's tel- related lower hydrate metatyuyamunite; the adjacent areas like Wyoming contain few Te- luride occurrences generally fall within a trian- minerals differ in their water content and form bearing deposits. In fact, Colorado has roughly gle, with one leg the northeast-southwest- reversibly from each other depending on 40 times as many telluride occurrences per trending Colorado mineral beit, another leg humidity conditions. The yellow uranium sili- square kilometer as Wyoming, and more than trending east from La Plata to an area southeast cate may form where the ore is low five times as many per square kilometer as an of Westcliffe (west of Pueblo), and a third leg in vanadium. It occurs as radiating clusters of average western mining state. New Mexico and trending roughly north from Westcliffe to acicular crystals on or bedd-ingsurfaces Utah are examples of typical westem mining jamestown, northwest of Boulder. A1l of New and occasionally as thicker felted masses or states in terms of Te occurrences Der souare Mexico's telluride occurrences lie in the south- showy acicular crystals in open spaces. kilometer, whereas Arizona contains roughly west part of the state except for two districts Schroeckingerite is rare in oxidized ore, occur- one third the number of Te occurrences of aver- northeast of Taos. Utah's telluride occurrences ring as light-green platy crystals that fluoresce age western mining states. are confined to the western half of that state. brilliant yellow green in short-wave Arizona contains telluride minerals with the Four hypotheses were tested to explain these radiation. broadest chemical diversity in the four-corner large-scale distribution patterns. The first con- Other scarce minerals in oxidized or oartiallv states. Most of this diversity is found in the cerns the distribution of alkalic rock complexes, oxidized deposits are the lead-uranium oxide Bisbee district, which contains more than half of with which telluride deposits are known to curite, the calcium vanadates hewettite and Arizona's tellurides. In fact. Bisbee's 18 report- commonly affiliate (Mutsihler et a1., 1985). The metahewettite, and two new minerals from the ed telluride species represent the largest num- four-corner states have anomalously high pro- Grants district: santafeite. a complex man- ber of telluride species in any depost that the portions of alkalic intrusions per square kilo- ganesevanadaie, and grantsite,a sodium calci- author is aware of in the world. In Colorado, meter of ground surface, yet they do not uni- um vanadate. Goldmanite, another new miner- the Jamesown district contains at least L6 unox- formly contain above-average numbers of tel- al, is a vanadium-rich related to andra- idized telluride minerals, which represent 65% luride occurrences within their boundaries. The dite and grossularite; ii occurs in the Lagr.rna of Colorado's telluride mineral varieties. second concerns the timing of peak alkalic areawhere a Todilto deposit extending into the Surprisingly, Utah has the least diverse tel- igneous activity. In Colorado this occurred (per- Entrada sandstone was intruded by a basaltic Iuride minerals of the four-corner states 26-76Ma ago, which is identical to peak alkalic igneous sill, forming various calc-silicate meta- haps becauseof inadeouateidentificatjon tech- activity in New Mexico and three other westem morphic minerals including andradite-grossu- niques), even though ii has the typical number states (Mutschler et aI., 1992), yet Colorado's larite. Small crystals of goldmanite formed in of occurrences per square kilometer. Another tellurides per square kilometer far surpass the vanadium-rich parts of the metamorphosed unexpected result of this investigation is that other four states'. The third hvpothesis con- deposit. certain statistical and geologic evidence sug- cerns plate tectonic relations, wtriitr do not pro- Several additional minerals occur in or gests that Arizona should contain more Te-bear- vide a clear answer. Finally, metal inheritance around the Todilto deposits; their relationship to ing mining districts than are presently known. tied to underlying basement lithology/age was uranium-vanadium mineralization is not cl-ear. The mineralogy of the telluride minerals in examined and was the most successful of the These include small quartz crystals, the four-corner states is fairly typical of Te-bear- four hlpotheses. Although it cannot yet be oxides, and iron oxides resembling . ing districts worldwide. The most reported tel- proved, the composition of Colorado's base- Coarsely crystalline black calcite and paragenet- luride mjnerals in the region are (in decreasing ment appears to be the most reasonable expla- ically later white calcite are common in fractures order of reported district-wide occurrences, nation for its anomalously high density of tel- and open spaces. Rare pyrite-coated scalenohe- with the number of reports in parentheses): pet- luride occurrences per square kilometer. dral calcite crystals are also observed. A few zlte (25), (22), altaite (18), tetrad).'rnite other minerals may occur as very minor con- (18), (16), (14), and native References stituents of the host rocks and possiblv of the tellurium (14). Detailed literature examination deposits; some have been reported or tentative- indicates that altaite, native tellurium, hessite, Mutschler, F. E., et al., 1985,Precious metal deposits ly identified in previous work but were not con- and tetradymite are perhaps the most comrnon- relatedto alkaline rocks in the North Amirican Cordillera-an interpretive review: Tians. Geol. firmed in this study. The most significant or ly reported telluride minerals worldwide, occur- Soc.S. Afr. 88:355J7. interesting minerals from the Todilto deposits ring in a broad range of geologic environments. Mutschler, F. E., et al., 1992, Alkaline and related are: uraninite, UOr; coffinite, U(SiOl)l ,(OHy*^; The presence of petzile, sylvanite, and calaverite igneous rocks and associatedmineral deposits-an haggite, !2O2(OH)3; paramontroseite.VOr; flu- in the above list suggests the relative prevalence album of space-timesnapshots of the Westem U.S. orite, CaF2; barite, BaSOn; pyrite, FeSr; c-lcite, of Au-tellurides in the four-comer states. and Canada: U.S. Geological Survey, MF Map CaCOr; hematite, FerOr; galena, PbS; tyuyamu- One might infer from above that the general Series,174 p. nite, Ca(UO2)2 (Y O 4)z 5-8y2H2O; metatyuyamu- trend is for areas with the most reported Te- nite, Ca(UO2)2 (Vot2 3-5HrO; uranophane, bearing minerals to contain the widest diversi- Ca(UOr)r(SiO, OH)z.5HzO; schroeckingerite, ty in their telluride mineral chemistry. This is Gpor-ocv AND MINERALocy oF TELLURruM pbfUro,, MINER- NaCarU:q(Co;),SooF totiro; curire, basically true. For example, Co.lorad'ohas at ALIZATIoN IN THE LoNE PtNr rrarun ente.

20 February 1996 New Mexico Geology Wrrcox DlsrRrcr, CATRoN CouNry NEw Primary mineralization occursas fracture fill- (CuTeO..2H2O),was also noted during MEXIco, by Virgil W. Lueth, New Mexico ings in veinlets in the silicified flow-banded this study (rajite was reported as a pseudomolph Bureau of Mines and Mineral Resources, rhyolite at most prospects.Disseminated min- of teineite by Williams, 7972). The presence of Socorro,NM 87801-4796;loan T. Beyer,5030 eralization is also oresent. At the Lone Pine copper tellurates in the absence of a primary Beyer Road, Las Cruces, NM 88011; and mine, primary mineralization occurs in larger copper phase is somewhat enigmatic. Howevel, RonaldB. Gibbs,PhelpsDodge Corp., Tyrone, pods in a large zone of silicified flow-banded the report of bismuthinite in the district also sug- NM 88065(5) rhyolite and silicified andesite.Primary miner- gests the potential for a number of bismuth tel- alization consistsof pyrite, fluorite, tellurium, lurates (srnimite, montanite, and chekhovichite) The Lone Pine mine area, in the Wilcox dis- and molybdenum. A precious-metal telluride, to be found in the area. There is potential for trict, Catron County, New Mexico, has been the (?), was identified for the first time in additional telluride minerals to exist in the dis- site of modest mineral production. The district the district during this study. A vertical miner- trict also, including bismuth and other precious has produced 5 tons of tellurium and less than alogical zonation is apparent with pyrite strati- metal varieties. Finally, the unique bonding char- 100 ouncesof gold and silver (1.23oz. Au and graphically lowest grading into pyrite-telluri- acteristics of tellurates hold promise for the dis- 19.0 oz Ag officially reported). The Wilcox dis- um assemblagefollowed by a fluorite-rich zone covery of new tellurate mineral species in the trict is also credited with the production of at the highest elevations.Tellurium mineraliza- area. L0,603tons of fluorite (McAnulty, 1978).Despite tion is strongestat the pyrite-fluorite transition the production of metal and fluorite, the area is zone. Ballmer (1932)reported bismuthinite in References probably best known for its telluriurn minerals. the ores, but the mineral was not observed in However,very little systematicwork onthe min- this study. Ballmer,Gerald J., 1932,Native tellurium from north- eralogy has been attempted prior to this study. As a result of the unique chemistry of telluri- west of Silver City, New Mexico: American The ore deposits are hosted by Tertiary vol- um- molecules and their behavior in the Mineralogist, v. 77, pp. 491492. canic and volcaniclastic rocks, mainly in the Crawford, R. D.,1937, Tellurim minerals of New weathering environment, tellurites and tellu- Mexico: American Mineralogist, v. 22, pp. Mogollon and Mineral Creek andesite units of rates are the most abundant tellurium speciesin (7979\. 1.055-1.069. Ratt6 et aI. Mineralization tends to be the district. and paratellurite (both McAnulty, W N., 1978, Fluorspar in New Mexico: confined to north- and northwest-trending fault TeO") were observed in the district for the first New Mexico Bureau of Mines and Mineral zonesthat were in turn intruded by flowband- time-, usually growing on native tellurium. In Resources,Memoi 34, 54 pp. ed rhyolite dikes. The rhyolites are bleached, additiory the weathering of pyrite and native tel- Ratt6,J. C., Gaskill, D. L., Eatory G. P, Peterson,D. L, silicified, and iron stained, to various degrees. lurium gives rise to a host of iron tellurate min- Stotelmeyer,R.8., and Meeves,H. C.,1979,Mneral The adjacentvolcanic rocks are argillized, local- erals including (FerTeuO,2HrO), resources of the Gila Primitive Area and Gila ly silicified, and strongly iron stained in places. mackayite (FeTe2O5(OH)), (FeTeO, Wildemess, New Mexico: U.S. Geological Survey, sonoraite pp. Previousworkers in the district attribute miner- Bdletin1451.,229 (OH).H2O),blakeite (Fer(Teo3)3)poughite (Fe2 Williams, S. A., 1979,Raiite, naturally occuning cupric alization to late-stage volcanism and buried (TeO.)r(SO/.3HrO), and perhaps other, more pyrotellurate, a new mineral: Mineralogical plutonism related to the development of the rare, iron tellurates ( and cuzticite). Magazine, v- 43, pp. 91,-92. tr ring cornplex of the Bursum caldera The district is the type locality for a copper tellu- (Oligocene). rate, rajite (CuTerO5).A secondcopper tellurate,