Amazonite:  K(AlSi3O8)

Amazonite is a green microcline feldspar, with a hardness on the Moh’s scale of 6-6-1/2.  It forms in the triclinic crystal system.  Studies suggest that the color is the result of small quantities of lead and water in the feldspar.  (Hoffmeister et. al. 1985).

 

Amazonite and smoky quartz, Tree Root Pocket – 31.5 cm wide.

 

Amazonite and Smoky Quartz on albite, Tree Root Pocket, 7.3 cm wide.

Amazonite and Smoky Quartz, from the Tree Root Pocket, Two Point Mine, 10.7 cm wide.

Amazonite and smoky quartz, Tree Root Pocket – 9.9 cm wide

Amazonite, smoky quartz and albite, Tree Root Pocket – 12 cm wide.

Amazonite and smoky quartz, Tree Root Pocket

Amazonite and smoky quartz, Tree Root Pocket

 

Amazonite and smoky quartz, Tree Root Pocket

 

Amazonite and smoky quartz – 8 cm wide.

 

Amazonite and smoky quartz, Tree Root Pocket – 10.2 cm high.

Amazonite and smoky quartz on albite – 8.3 cm high.

Amazonite and smoky quartz – 6.3 cm high.

Amazonite and smoky quartz – 17.1 cm high.

Amazonite and smoky quartz, Tree Root Pocket – 9.9 cm wide.

Amazonite and smoky quartz with albite, Tree Root Pocket – 15.4 cm wide.

Amazonite and smoky quartz, Tree Root Pocket – 10.8 cm wide.

 

Amazonite and smoky quartz, Tree Root Pocket – 17.1 cm wide.


OTHER MINERALS:

Other notable minerals found in the Crystal Peak Mining District are described below.  However, this list is not inclusive.

Albite:  Na(AlSi3O8)

Albite is often found with amazonite and smoky quartz in the area as a variety called cleavelandite.  Albite is a plagioclase feldspar.  The color of the cleavelandite is generally white and often forms in ‘rosettes’ or ‘sheaves’ providing a nice contrast to the green amazonite and smoky-colored quartz.

Betrandite:  Be4(Si2O7)(OH)2

Bertrandite was reportedly found in the 1980s in a pocket north of Crystal Peak with amazonite and smoky quartz by Chuck Baldwin and John and Barbara Muntyan.  Two blocky clear thumbnail size crystals approximately 2.5-3 cm long were found loose in the pocket.

Cassiterite:  SnO2

Two amazonite plates from the Two Point mine were found to contain 1.5 cm cassiterite crystals.

Fluorite:  CaF2

Fluorite is occasionally found in combination with the amazonite and smoky quartz, though more often separately as single or combination cubic crystals.  Color varies from clear to green to blue to purple.  Crystals to 3 inches have been found.

Goethite:  FeO(OH)

Goethite is an iron oxyhydroxide containing ferric iron and is often found in pockets of amazonite and smoky quartz.  Often the presence of pockets is signaled by the reddish color imparted by associated iron oxide.

Goethite from the Crystal Peak Mining District is frequently found as brown or black masses, but occasionally nice lustrous sprays are found.  Goethite has also been seen as needles within smoky quartz crystals.  It has also been known to replace other minerals, such as siderite, forming unique pseudomorphs.

Orthoclase:  Ka(AlSi3O8)

The blue-green form of microcline orthoclase feldspar is called amazonite.  The microcline distinction is that it is a low temperature polymorph of orthoclase.  However, it is worth mentioning here that brown to white microcline orthoclase has been found in the area as well.

Quartz:  SiO2

In addition to the well know smoky quartz, clear quartz crystals have also been found in the Crystal Peak area, some displaying sceptors. 

Topaz:  Al2(SiO4)(F,OH)2

Topaz has been found in the Crystal Peak area, but is not common. 


CURRENT STATUS:

Mining by Collector’s Edge Minerals, Inc., continued at or near the locality for several years, but results are not summarized here.  The district continues to produce amazonite and smoky quartz along with other minerals, though most collecting is by hand which limits the amount of specimen material available to the collector. 

ACKNOWLEDGEMENTS:

Collector’s Edge wishes to thank Bill Tanaka for his help in creating the graphics for this article.  Also, Collector’s Edge wishes to say goodbye to George Robertson, a faithful friend and partner on the Two Point project, who passed away just three months before the “big find”.

REFERENCES:

Foord, E. E., Martin, R. F. (1979) Amazonite from the Pikes Peak batholith. Mineralogical Record, 10, 373-3 84.

Gross, E. B. (1962) Alkalic granites and pegmatites of the Mount Rosa area, El Paso and Teller Counties, Colorado. PhD thesis, University of Michigan, 173 pp.

Hoffmeister and Rossman (1985). “A spectroscopic study of irradiation coloring of amazonite; structurally hydrous, Pb-bearing feldspar”. American Mineralogist 70: 794–804.

McNulty, L. (1983) Personal communications with the owner of the Old Gem Mines.

Odiorne, H.H. (1978) Colorado Amazonstone, the treasure of Crystal Peak. 51 pp. Forum Publishing Co., Denver.

Pearl, R. M. (1974) Minerals of the Pikes Peak granite. Mineralogical Record, 5, 183-189.

Wobus, R. A. (1976) New data on potassic and sodic plutons of the Pikes Peak batholith, central Colorado, in Professional Contributions of the Colorado School of Mines, Studies in Field Geology, edited by R. C. Epis and R. J. Weimer, 8, 57-67.