Some of the finest turquoise is found in the Southwest part of the United States. Especially in the the states of Nevada, Southern Colorado, New Mexico, and Arizona. Turquoise generally forms in seams and veins, the graphic above is a fine piece from Battle Mountain, Nevada. Much of the material surrounding the turquoise vein is limonite, which must be removed. Some of the gem stone is lighter and the more desirable, darker.
  My brother Marc, who, amongst his many talents, is an excellent silversmith and gem cutter, had the enviable task of locating the fine turquoise which was used in the studio. The above piece of rough was acquired during one of the rare times I was fortunate to be able to accompany Marc on his adventures.
  His travels took him to all the mentioned states. He would purchase the rough, bring it back to the studio in Breckenridge Colorado to slab, cut, shape, and polish.

Some of the stones on this tray are from the above rough. The rest are Spiderwebs from the #8 mine. The limonite matrix surrounds many fine nodules of gem grade turquoise. Once the mass of limonite is removed, the real art is in slicing, shaping, and cutting to expose the blue of the gem. Sanding with many grades of paper/grit is required to smooth the stone before the actual polish is applied.
BELOW are some examples of fine spiderweb or "cobweb" turquoise. Only certain mines will produce this rarest material. It consists of clusters of irregular or deckle-edged bits of turquoise held together by matrix which thinly outlines the material. The old #8 mine north of Carlin, Nevada produced some of the finest stones.
#8 Spiderweb
SpiderWeb Turquoise

#8 Spiderweb
  SpiderWeb Turquoise
Kingman with pyrite and quartz
Here is an excellent example of fine Kingman. Note the pyrite
and the inclusion of a quartz crystal at the lower right.

CLICK here for much more about TURQUOISE at this fine web site.
Some fine maps of the major US Turquoise mines may be found here.

Brazilian Agate Slices        Malachite
Picture stones

All of my jewelery is stamped with this hallmark:

All Design and Art: Joel R. Cheves 1975 - 2001