TURQUOISE USED IN AMERICAN INDIAN JEWELRY
Turquoise comes in all shades of blue, to blue-green, with a possible shading towards brown-veined greens. Matrix (veining) may or may not be present in any color(s). It is the natural variations in turquoise that make it appealing. The color of turquoise in American Indian jewelry ranges from brownish green to bright blue.
Not All Turquoise is Created Equal
If you are looking at two turquoise bracelets one at $30 and the other at $500, what is the difference? Well, there are many uses and misuses of the word turquoise.
Natural Turquoise is a stone that has not been altered in any way. It is the way it was found in nature. Natural Turquoise looks very real and beautiful but, over time, when exposed to light, sweat, perfume, makeup, oils and detergents, it can deteriorate (crumble) and lose its color or change color to a pale green. It can also lose its structural stability and crumble and crack. To deal with these problems, methods have been developed to preserve turquoise. Manufacturers and dealers use the following terms in a non-standard fashion, so if you are ever in doubt when purchasing a turquoise item, you should ask about the origin of the turquoise and its treatment.
Enhanced usually refers to a natural stone that has been treated with electrical currents that hardens the stone and enhances the color. Nothing else is done to the stone. Enhanced turquoise should not change color over time.
Stabilized turquoise has been impregnated with an acrylic or epoxy to harden the stone and enhance the color. Almost all turquoise used for heishi necklaces and fetish carvings is stabilized because otherwise the heishi would quickly fade and break.
Compressed stones have been hardened by extreme pressure.
Artificial or Imitation Turquoise – There are a number of manufactured turquoise products, some of which look like real stone and others that look like plastic. Some minerals, like howlite, can be dyed to look like turquoise.
Synthetic and Lab Grown Turquoise have the same chemical composition and physical look of natural turquoise.
Block Turquoise is manufactured in blocks and is made to look like turquoise. It may be all plastic polymer or it may have crushed or powdered turquoise or other stone mixed with resin or polymer. Block Turquoise sometimes has swirls or blobs of dark dye added to simulate the look of matrix.