Amethyst is the purple variety of the mineral Quartz, and is its most famous and valuable gem variety. Quartz also contains other gemstones such as Citrine, Rose Quartz, and Smoky Quartz. The color of Amethyst is most often caused by iron impurities, though it can also be colored by natural radiation exposure. Amethyst is sometimes heat treated to deepen the color, or to …

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 means "not drunken", as Amethyst in antiquity was thought to ward off drunkenness. The color of some Amethyst specimens from certain localities slowly fade upon prolonged exposure to light. …

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. Although Amethyst, the purple variety of Quartz, and Citrine, the yellow/orange variety of Quartz belong to the same scientific mineral classification, they have always been distinguished as …

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 of Quartz, but other forms also make important gemstones. Chalcedony describes any form of Quartz that is microcrystalline, in compact form without any visible crystal s. Chalcedony also …

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

PERIODIC TABLE of the ElementsThe Periodic Table of Elements

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 belong to the same scientific mineral classification, they have always been distinguished as …

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, which is a dense, course grained rock formed at extremely high pressures. It is occasionally associated with Diamond in Diamond deposits.

Fluorite makes a beautiful gemstone that comes in all colors, and can often be multicolored with two or more contrasting color within the same gemstone. Multicolored Fluorite gemstones often show banding patterns. Large and flawless crystals are fairly common, and these can produce very large and totally clear gemstones. However, due to Fluorite's very low hardness and …

Citrine is the yellow to brownish-red variety of the mineral Quartz. It is a widely used as a gemstone, and after Amethyst it is the most popular Quartz gem. Most Citrine is formed by heat treating purple Amethyst. Citrine may also be produced by heat-treating Smoky Quartz from certain localities. In some Amethyst deposits, the Amethyst has been partially or fully changed …