Quartz is one of the most abundant minerals in the earths crust and can be found in many different varieties, including: amethyst, aventurine, citrine, tiger eye, rose quarts, jasper and calcedony. Calcedony is a crypto crystaline (a fine internal crystal structure, that doesn't look crystaline) form of quartz. Calcedony has again many variants, including: agate, carnelian, chrysoprase and onyx. Calcedony is a semi-precious gemstone.Top
Chemical & Physical Information
|Chemical Name||Silicon Dioxide|
|Crystal habit||6-sided prism with 6-sided pyramids as end.|
 Specimen from my personal collection, photo taken by me.