Genuine, naturally occuring Turquoise is quite expensive and getting rarer every day as known mines are mined out and closed. In fact, only about 25% of the once prolific Turquoise mines are still in operation the American Southwest. Moss to lime green to yellow in color, these bead strands may also show russet, white, grey and olive matrix. Commonly called yellow turquoise because it occurs in the same mines, this natural material is a delicious blend of quartz and jaspers.