“Beads of quartz have been found in caves in Israel that were occupied between 5,000 and 6,000 years ago.” Clearly quartz has been valued over time as a stone of worth for adornment.
There are many varieties of stone in the quartz family. Many are commonly known as quartz: rose quartz, smoky quartz, blue quartz, milky quartz, tourmalinated quartz, rutilated quartz, strawberry quartz, amethyst, and even citrine. However, there are still others less commonly known to be quartz.
- Aventurine – usually a milky medium to dark green colored stone but it may be a metallic orange-brown color
- Dumortierite quartz – a rare violet-blue to denim-blue colored stone
- Prasiolite – a pale green stone that may be anywhere from transparent to translucent; most prasiolite is created by heating amethyst or citrine
- Tiger’s eye/hawk’s eye – tiger’s eye has brownish yellow – golden brown/green colors while hawk’s eye has darker blue/black colors; both have the “cat’s eye” effect (chatoyancy) because of the way quartz filled in for the asbestos in the rock fibers as the stone formed
 The Jeweler’s Directory of Gemstones by Judith Crowe, p.67