Tuesday, August 17, 2010

GEMSTONE JEWELRY - an old stone Revisited !

Using unique or unusual one-location gemstones allows one to create a one-of-a-kind piece of jewelry, especially when the history of the gemstone can be traced back to the Vikings.

Being able to acquire the unusual gemstone known as Labradorite, allowed for the creation of this necklace set. Pieces of Labradorite cut into puff-rectangles as highlight gemstones are combined with Mother-of-Pearl rondels and silver plated -chain links to form the necklace. French hook earrings with rondel Labradorite and MOP beads completes the set.
Labradorite is a feldspara intermediate to calcic member of the plagioclase series. Streak seen within the stone is white, like most silicates. Twinning is common. As with all plagioclase members the crystal system is triclinic and three directions of cleavage are present, two of which form nearly right angle prisms. Labradorite occurs as a nearly clear, white to grey rocky to lath grained rock. Labradorite is found on Paul's Island near the town of Nain in Labrador, Canada. It occurs in large crystal masses in anorthosite and shows a play of colors called labradorescence. The labradorescence, or schiller effect, is the result of light refracting within lamellar intergrowths resulting from phase exsolution on colling in the Boggild


miscibility gap. Gemstone varieties of labradorite exhibiting a high degree of labradorescence are called Spectrolite: Moonstone and Sunstone are also commonly used terms, and high-quality samples with good qualities are desired for jewelry. A variety of Labradorite that comes from Norway is called Larvakite. Larvakite originates from the town of Larvik in Norway, where this type of igneous rock is found. The crystallisation of this ternary feldspar indicates that Larvakite began to crystallise under lower crustal conditions than did Labradorite. Larvakite posses the same labradoresence characteristics as Labradorite and the two can eaasily be confused.

Mother of pearl, also called nacre, is an iridescent layer of material which forms the shell lining of many mollusks. Pearl oysters and abalone are both sources of mother of pearl, which is widely used as an inlay in jewelry, furniture, and musical instruments. Mother of pearl comes in several natural colors, and is often bleached and dyed for decorative use. The dye retains the shimmering layers which make mother of pearl so sought after. Depending on the shell the Mother of Pearl is taken from, it may be processed into large flat or curved pieces, small pieces sometimes call nuggets or processed as polished beads. Two substances actually combine to create mother of pearl. The first is plates of aragonite, a material which is secreted by the mollusk. Aragonite contains calcium carbonate and conchiolin, a natural protein. Alone, the plates are very hard, but also very brittle. As a result, the organism also secretes an organic material similar to silk to layer between the plates. The result is a strong, flexible material which can withstand hard use.