Detailed gem and jewelry information guide about the purple quartz gemstone amethyst.

Amethyst is a well known mineral and gemstone. It is the purple variety of the mineral Quartz, and its most valuable and prized variety. Its name derives from the Greek "amethystos", which …

Amethyst from Rhode Island from Diamond Hill, Ashaway, south of Hopkinton, Washington County, Rhode Island

Ametrine is a unique gemstone in that it is essentially combined of two separate gemstones. Although Amethyst, the purple variety of , and Citrine, the yellow/orange variety of Quartz …

Ametrine is a relatively new gem term, and the word is a combination of Amethyst and Citrine. Ametrine is a unique gemstone in that it is essentially combined of two separate gemstones. …

Quartz is one of the most common and varied minerals on earth, and its abundant colors produce many gemstone types. Amethyst and Citrine are the most popular and valuable gem varieties …

Citrine is the yellow to orange variety of Quartz. Natural Citrine is not common; most Citrine on the gem market is produced by heat treating Amethyst and Smoky Quartz. It takes a relatively low …

Omphacite is a rare member of the pyroxene group. It is intermediary in chemical composition between Augite and Jadeite. It is one of the primary minerals that forms eclogite deposits, …

PERIODIC TABLE of the ElementsThe Periodic Table of Elements

Detailed description, properties, locality information guide about the obsidian mineral cristobalite (quartz polymorph).