Moonstone is a mineral from the feldspar group that displays a pearly and opalescent play of color caused by light diffraction within its crystal structure. Moonstone has been used in jewelry for millennia, including ancient civilizations such as the Romans, who admired it because they believed it was born from...

  Lapis Lazuli is a semi precious stone formed during the metamorphosis of chalk into marble. It has a cubic crystal system, and is in the mineral class of lattice silicate. Lapis Lazuli has been prized since antiquity for its intense blue color, and has been mined since 7th Millennium...

Common opal, sometimes known as “potch”, is a variety of opal that does not exhibit the flash and play-of-color seen in precious opal. However, common opal occurs in a variety of beautiful colors that includes a range of wonderful pastels including yellow, blue and pink. Most deposits of common opal...

Turquoise is one of the of the first gemstones to be mined and has long been prized for its intense colors, which vary greatly from sky blue to green, depending on the quantities of iron and copper found in it.  Even though turquoise is found around the world, the right...

Goldstone is a manufactured material composed of copper flecks suspended in glass to create an effect called "aventurescence" similar to metallic glitter. Depending on the color of its base, goldstone can be blue, brown or green. Pictured below is a silver and goldstone thimble dated to 1908. Urban legend says...

Malachite is a copper carbonate hydroxide mineral typically found as stalactites and botryoidal coatings on the surfaces of underground cavities.  The mineral was given this name, of Greek origin, due to its resemblance to the leaves of the mallow plant. When this material is cut into slabs and pieces, the...

Rhodonite is a pink manganese silicate mineral of variable composition that often contains significant amounts of iron, magnesium, and calcium in the form of black dendritic veins. This mineral was officially named Rhodonite from the Greek rhodon, meaning “rose,” in 1819. It has also been referred to as Peach Blossom...

Variscite is a rare mineral formed by phosphate rich water deposits that react with aluminum rich rocks in a near-surface environment. It is rarely found in crystals that are large enough to see without magnification, instead it usually occurs in veins, or cavity fillings. Variscite was originally discovered in Germany...

Opal is the product of seasonal rains that drenched the ground in dry regions such as Australia’s semi-desert “outback.” The showers soaked deep into underground rock, carrying dissolved silica downward, which evaporated during dry periods, leaving solid deposits of silica in the cracks and between the layers of underground sedimentary...

Also known as Nacre, is an organic–inorganic composite material produced by some mollusks as an inner shell layer; Mother of pearl is found in the outer layer of cultured pearls and the inside layer of pearl oyster and freshwater pearl mussel shells. It is strong, resilient, and iridescent. Nacre is...

Sugilite is a very rare purple cyclosilicate mineral that was named after the Japanese petrologist, Ken-ichi Sugi, who first identified it in 1944 in the Iwagi Islet. This gemstone gets its attractive purple color from traces of manganese, and it can range in color from pinkish-purple to deep bluish-purple.  A significant...

Labradorite is a member of the Feldspar family and is treasured for its remarkable play of color, known as labradorescence.  The stone, usually a smoky quartz-looking gray-green, dark gray, black or grayish-white, is composed of aggregate layers that refract light as iridescent flashes of peacock blue, gold, or pale green.  Labradorite...

Onyx is the most traditional black gemstone, and it is the name used to commonly refer to solid black Chalcedony, or a banded or layered black and white Chalcedony. Onyx combines translucent and opaque bands consisting of fine intergrowths of silica minerals quartz and morganite. Its bands are parallel to...

Some specimens of common opal display a fluorescence under short-wave and long-wave ultraviolet light. Most fluorescent opals range in color from bright white to buttery yellow and exhibit a bright green color under fluorescent light, but blue and white fluorescence is also encountered.  The main reason for its fluorescence is...

Opal Matrix is a treated opal that comes largely from a field called Andamooka in South Australia. This particular kind of opal presents a porous host-rock composed by a conglomerate of sand filled with very small grains of precious opal. Since the sand is light in color, the colors of the...

Jasper is a metamorphic rock formed when volcanic ash is cemented into a solid material. The result is a dense, opaque variety of Quartz that occurs in nodules or as fillings in fissures in nearly every color.  Jasper can be found all over the world, and historically is traceable to...

Porcelain is a white ceramic material made by heating substances, generally including a material like kaolin, in a kiln to temperatures between 1,200 and 1,400 °C (2,200 and 2,600 °F). Relative to other ceramic materials, porcelain is uniquely strong, and translucent, as a result of its partial transformation into glass...