Onyx is a microcrystalline quartz, which has traditionally been used in cameo jewelry or made into beads or cabochons. Finely textured and usually black in color, onyx is an ancient stone used as early as Second Dynasty Egypt for bowls and other vessels.
Highly regarded by ancient civilizations for its unique aqua coloring, turquoise is a rare phosphate of copper that only forms in the earth's most dry and barren regions. The name turquoise derives from the fact that this gemstone was brought to Europe from eastern Mediterranean traders, known as Turks. Colors can range from green and greenish blue to sky blue. Turquoise is a birthstone for December.