March 17th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Topaz is a silicate mineral of aluminium and fluorine with the chemical formula Al2SiO4(F,OH)2. Pure topaz is transparent but is usually tinted by impurities; typical topaz is wine or straw-yellow.
Tags: gemstones, jewelry, sagittarius, topaz, zodiac
March 17th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
The mineral beryl is a beryllium aluminium cyclosilicate with the chemical formula Be3Al2(SiO3)6. The hexagonal crystals of beryl may be very small or range to several meters in size.
March 17th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Peridot is the gem quality variety of forsteritic olivine. The chemical composition of peridot is (Mg, Fe)2SiO4, with Mg in greater quantities than Fe.
March 17th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Carnelian, sometimes spelled cornelian, is a red or reddish-brown variant of chalcedony. The word is derived from the Latin word meaning horn, in reference to the flesh color sometimes exhibited.
March 17th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Onyx is a banded variety of chalcedony, a cryptocrystalline form of quartz. The colors of its bands range from white to almost every color (not including shades such as purple, blue, or black).
March 16th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Emerald is a variety of the mineral beryl, colored green by trace amounts of chromium and sometimes iron. Most emeralds are oiled as part of the post lapidary process. Emeralds come in many shades of green and bluish green. Most emeralds are highly included, so it is quite rare to find an emerald with only minor inclusions. Emeralds in antiquity were mined by the Egyptians and in Austria, as well as Swat in northern Pakistan.
March 16th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Agate is a term applied not to a distinct mineral species, but to an aggregate of various forms of silica, chiefly chalcedony. Most agates occur as nodules in volcanic rocks or ancient lavas where they represent cavities originally produced by the disengagement of volatiles in the molten mass which were then filled, wholly or partially, by siliceous matter deposited in regular layers upon the walls.
March 16th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Sapphire is the single-crystal form of aluminum oxide (Al2O3), a mineral known as corundum. The corundum group consists of pure aluminum oxide. Trace amounts of other elements such as iron, titanium and chromium give sapphires their blue, yellow, pink, purple, orange or greenish color. Sapphire includes any gemstone quality varieties of the mineral corundum except the fully saturated red variety, which is instead known as ruby.
March 16th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Chalcedony is one of the cryptocrystalline varieties of the mineral quartz, having a waxy luster. Chalcedony may be semitransparent or translucent and is usually white to gray, grayish-blue or some shade of brown, sometimes nearly black.
Tags: aries, bloodstone, chalcedony, gemstones, jewelry, zodiac
March 16th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Amethyst (SiO2) is a violet or purple variety of quartz often used as an ornament. In the 20th century, the color of amethyst was attributed to the presence of manganese. On exposure to heat, amethyst generally becomes yellow, and much of the citrine, cairngorm, or yellow quartz of jewelry is said to be merely “burnt amethyst.”
March 16th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Garnet is a group of minerals that have been used since the Bronze Age as gemstones and abrasives. The name “garnet” comes from the Latin granatus (”grain”), possibly a reference to the Punica granatum (”pomegranate”), a plant with red seeds similar in shape, size, and color to some garnet crystals.
March 16th, 2007 | Jennifer Martin | Zodiac Sign Gemstones, Columnists
Natural rubies are exceptionally rare, but synthetic rubies (sometimes called created ruby) can be manufactured fairly cheaply. Rubies are mined in Africa, Asia, Australia, Greenland, Madagascar and North Carolina. The unique color in Myanmar (Burmese) rubies is described as “pigeon’s blood”. They are known in the trade as “Mogok” rubies.
