Edna B. Anthony

The sorosilicate class of minerals is composed of more than seventy minerals. Most are rare, and only a few are...

Dioptase incorporates the native metal, copper in the Si6O18 ring structure with water to form the only gem material that...

Tanzanite! Baron Sigismund Zois von Edelstein of Slovenia could never have imagined that a variety of the mineral he discovered...

One of the most beautiful blue gemstones is native to our own country. In 1906, a prospector found what he...

Andalusite, kyanite, and sillimanite all contain identical amounts of aluminum, silicon, and oxygen, combined with other trace elements. I find...

Previous articles discussed the polymorph gemstones andalusite, sillimanite, and kyanite of the Al2SiO5 group of the nesosilicates. Topaz and staurolite...

Lets Talk Gemstones - Zircon is the single member of the zircon group of the nesosilicates that is suitable for...

The region of pegmatite dikes in the state of Minas Gerais in Brazil has been the primary source of gem...

Staurolite! Why would one of the most ordinary, patently unattractive minerals, used as a religious talisman and a good luck...

On an excursion in the Alps in 1797, mineralogist, R. J. Hauy discovered some highly vitreous, piezio-electric wedged-shaped crystals that...

Goshenite is the transparent, colorless, alkali-bearing pure beryl that was discovered in Goshen, Hampshire County, Massachusetts. The Lily Pond mine...

Yellow-green beryl has achieved 'desired gem' status with consumers just within the last few years. Museums were eager to acquire...

The varieties of beryl found worldwide include one of the most prized and one of the lesser valued of gemstones....

Richly colored morganite gems are among the more valuable of the secondary gemstones. The value of morganite has increased with...

Opal is a fascinating gemstone with an ancient history. Pliny the Elder gives an eloquent description of opal, comparing its...

Silicates comprise about a quarter of the known minerals and almost 40% of the common ones. The basic unit of...

With the exception of orthorhombic zoisite (tanzanite and thulite), discussed in the first article on the sorosilicate class of minerals,...

Australia's most famous opal mines lie on the periphery of this Great Artesian Basin. Mintabie, Coober Pedy, Andamooka, White Cliffs,...

Peridot, often called olivine and chrysolite, is a gem variety occurring in the solid solution series between fosterite (Mg2SiO4) and...

Garnet is a common mineral distributed worldwide. It occurs as crystals, in massive and granular forms, and as tumbled pebbles....