Turquoisein New byRobert H. Weber, Senior Geologist NewMexico Bureau ol Minesand Resources, Socorro, NM

Turquoise deposits are widely numeroustechnical reports dating from The mine was particularly note- distributedin New Mexicoin a triangular- l 858. worthy for both the quantity and quality shapedregion extendingfrom Santa Fe Major depositsare localized in two sep- of turquoiseproduced. Mine development County at the northern apex to Otero, arateclusters 3 mi apart, on Mount Chal- extendedacross a fracturedzone 40 to 60 Dofra Ana, and Grant Counties in the chihuitl and TurquoiseHill, a few miles ft wide on four adit levels,with a large south. The principal depositsthit have north of Los Cerrillos.Extensive prehis- open pit later excavatedfrom the second beensources of significantproduction are toric workings are noteworthy at both level to the surface.The best distributedin four districts:The Cerrillos localities. Turquoise occurs as narrow wasrecovered within 100ft of the surface, district near Los Cerrillos in Santa Fe veinletsand nodules ranging in color from with a remarkableconcentration in the County: the Burro Mountainsdistrict in paleto bright bluethrough bluish to "Elizabeth pocket" extending 150 ft the vicinity of Tyrone,Grant County; the dark greenset in a matrix of alteredmon- alongthe vein, acrossa width of up to 40 Eureka (Hachita) district near Hachita, zoniteand latite. staining ft. and overa verticaldistance of 40 to 60 period Grant County; and the Orogrande of the matrix is common; occasionalin- ft. Production estimatesfor this (Jarilla) district near Orogrande,Otero clusionsof in turquoisehave been rangefrom $2 million to $4million for the County. noted. Azure mine alone, and up to $5 million Minor occurrenceshave been recog- Modern production bY non-Indian for the entire district. The former nizedin the White Signaland SantaRita miners beganin the 1880's,reached a turquoise-producingproperties now are districts in Grant County, the Organ peak during the 1890's, and declined controlledby PhelpsDodge Corporation' yearsof the 20th district in Dofra Ana County, and the rapidly during the early Eurekadistrict Nogal district in Lincoln County. Other century,although intermittent production Turquoise deposits of the Eureka reported occurrencesremain unverified; in the district continuedat the Bell district. on the easternside of the Little probably the mineral is more widely dis- mine until 1925.Estimates of production Hatchet Mountains about 6 mi west of tributed in minor amountsthan has been valuesvary *idely, reportedlyexceeding Hachita, were rediscoveredin 1885by recognized. $2 million from operationsof the Amer- SterlingBurwell and Con Ryan while ex- Inasmuchas all known depositsare on ican TurquoiseCo. The bulk of this pro- ploring ancient diggings for they patented or unpatentedmining claims, duction was from the Tiffany (Castilian) believedhad beenmined there by and leaseholdson State lands, express mine at TurquoiseHill, reputedto have early Spaniards. Turquoise permissionof the claim owner or lessee yieldeda higherproportion of high-grade or continuedintermittently in the districtfor must be obtainedprior to enteringprop- gem materialthan any other mine in the next 25 years.Mines developed during erty to collector prospectfor turquoise. United States.Some estimates place the the period includedthe Azure, , The significanceof turquoiseto prehis- total productionof the district as high as this Galilee. Aztec, and the American Tur- toric inhabitants of the region is evi- $9 million. Renewedinterest in the Cerri- quoiseCompany. The turquoiseoccurred denced by the ancient workings (with llos district in the last few years has in irregular seamsup to one-half inch associatedprimitive mining tools)that led stimulated exploration for and thick in altered,fractured, and limonite- to the rediscoveryof major depositsin the turquoise,but dataon any turquoisepro- monzonite;also to a lesserextent late 1800's.Although the beginningsof ductionare lacking. stained in andesiticto basaltic volcanic rocks, this industry are obscure,archeological Burro Mountainsdistrict sandstoneand diorite. Clay mineralsand evidenceextends to circa200 B.C. During tur- commonly were associatedwith the intervalof approximately900 to 1650 In the Burro Mountains district, Fine gem-quality stones A.D., turquoisewas intensively exploited, quoisehas been recovered from a number the turquoise. about6 wererecovered in colorsthat rangedfrom and in the form of beads,, inlay of minesand prospectsin an area of Ty- paleblue throughdark to green- and mosaicwork, becamea widespread mi southwestof the new townsite as ish blue, the paler varietiestending to be trade commodity throughout the rone. Turquoiseis widely distributed zonesin relativelysoft. Many stoneswere finished Southwestand Mexico. The recoveryof veinletsand nodulesin fractured porphyry in attractive yellow and brown - more than 65,000pieces during excava- and -monzonite ac- stainedmatrix pieces;cameos were cut tions at PuebloBonito in ChacoCanyon highly alteredto kaoliniteand sericite The tur- from someof the seamsin whicha tightly indicatesthe magnitudeof turquoisetrade companiedby secondarysilica. color in bondedbrown matrix servedas the base with regionslacking local sources. quoiseexhibits a wide range of variousshades of blue and green,and in- for the carving.No production data are Cerrillosdistrict cludes some of the finest gem-quality availableeither for pastor currentopera- Deposits in the Cerrillos district are material found anywherein the world. tions in the area, but evidentlythe total particularlywell known from both arch- Pure nuggetsup to 1500carats have been yield has been small comparedwith the eologicaland historicalrecords spanning recovered. Cerrillosand Burro Mountainsdistricts. was madein a periodfrom about900 A.D. throughthe The "original" discovery Orograndedistrict Spanish Colonial and American occupa- l8?5 by John E. Colemanat the siteof As in the previouslydescribed districts, tions of the region. In terms of historic prehistoricmine workings.Major mining prehistoricworkings in the Jarilla Moun- significanceand production,Cerrillos tur- activity took place from 1890-1910at a few miles north of Orogrande, quoiseis pre-eminentamong the deposits severalproperties, including the Azure, tains, of the United States, evidenced by Parker,and Porterfield(Maroney) mines. ]:F

New Mexico Geology August 1979