Often very colorful, but sometimes with either one color or very muted colors. A mixture of different kinds of rocks or crystals. A gemstone of the quartz family ranging in color from pale lilac to deep purple. A form of beryl next in desirability to emerald. Colors range from pale to deep blue or blue green.
Barium sulfate occurring in blue, green, brown, and red.
Beryllium aluminum sulfate that is colorless in its pure form. The act of creating a cabochon. A common shape for a gem, usually with an elliptical perimeter and a domed top. Calcium carbonate that occurs in clear crystals as well as white, brown, red, yellow, and blue. Ammonites and baculites are typical of cephalopods.