Tuesday, June 21, 2011

Tiger's Eye is the Gemstone of the Week

The gemstone of the week this week is Tiger's Eye. There are several variations on the name, among them Tiger Eye and Tigereye. All the names refer to the silky, golden brown gemstone of the quartz family. It is a brown quartz silcon dioxide with yellow and brown parallel fibers. Iron oxide gives the stone it's yellow gold color. The glitter on the surface of the stone is known as chatoyancy (sha-toy-ancee).
Tiger's Eye is a vitreous stone-hard, unbendable and glasslike. On the Moh scale it is a 7. This makes it suitable for all types of jewelry, although care should be taken against exposing it to sudden temperature changes, as that could cause the stone to crack.

Tiger's Eye is usually cut as cabochons as this best shows off the chatoyancy and color. Heat treatment is the usual enhancement for this gemstone. Red Tiger's Eye is heat treated. The heat oxidizes the iron and turns it red. Years ago, I had some Tiger's Eye stones. My mom and I put them on a cookie sheet, in a 325 degree oven for 12 hours and they turned a lovely red. To prevent cracking,we did not preheat the oven, but put the stones in the oven, then turned it on, allowing the stones to gradually warm. Every couple of hours, we would turn the stones with tongs. We also left them in the oven to gradually cool down after we turned the oven off.
Tiger Eye is mainly found in South Africa, but is also found in Austrailia, Myanmar, Namibia and California.
Tiger Eye is said to help lower blood pressure, help with asthma and heart disease. It is also believed to pull someone into a more flexible and positive attitude and give the wearer courage and confidence. Roman soldiers often wore carved Tiger Eye into battle.

In these photos, you can see the different banding and how each stone varies.

Wednesday, June 8, 2011

Moonstone is the Gemstone of the Week

Moonstone, the gemstone of the week, is also the European birthstone for June.  This mysterious beauty has been used for jewelry since before AD 100. The ancient Romans believed that is was created from the solidified rays of the Moon. It is considered to be the second birthstone for the month of June. During the Art Nouveau period, this was a very popular gemstone. Famous jewelry houses such as Cartier's and Tiffnay used it in a lot of their pieces.
Moonstone is a member of the feldspar family, and is a potassium aluminum silicate. It is an opalescent stone and, like Labradorite, has flashes of color called schiller. In Moonstone, schiller is more often called adularescence-a billowy, floating color effect. It comes from the word “adularia” which was the first name for this gemstone. It was called after the first place moonstone was found, Mt. Adular, in Switzerland. Adularescence is created when light falls between two layers of feldspar that have intermixed, causing the light to scatter, producing the schiller effect.
On the Moh scale, Moonstone is a 6-6.5. The colors can range from blue, peach, green, pink, yellow, brown or gray, all with a silvery sheen. Rainbow Moonstone is a milky white with a rainbow sheen. The most valuable moonstone is one that has a colorless, transparent to semi-transparent appearance with a vivid blue adularescence. Ideally, the sheen should be centered to the top of the gemstone. Moonstone is found in Brazil, Madagascar, Europe, Myanmar, Tanzania, and in the U.S. in Pennsylvania and Virgina. The highest quality gemstones come from Sri Lanka. They are most often cut in cabochons to best display their adularescence.
Moonstone is believed to refresh memory, soothe and balance emotions and act as a digestive aid. It is also believed to heal strife between lovers and awaken passion.

Here are some of the moonstones I have.
Rainbow briolettes, rainbow faceted beads, peach, rainbow, white and gray and faceted peach beads.

Thursday, June 2, 2011

Pearls are the Gemstone of the Week

The birthstone for June, Pearl, is the gemstone of the week. This precious gemstone has been used in jewelry and ornamentation for centuries.
Most gemstones are minerals, but Pearls are organic and formed by living organisms. They are formed in the soft tissue layers of mollusks, such as oysters and mussels and begin forming when an irritant such as sand, gets inside the shell. They are made of calcium carbonate and organic conchiolin, that build up as concentric layers . (If you cut a pearl in half, the inside layers would resemble tree rings.)This is done in order to protect the inside of the oyster or mollusk from the irratant. This process can take anywhere from 4 months to 7 years. The longer it takes, the larger the pearl.

There are two basic kinds of Pearls-natural and cultured. Natural pearls occur in nature without assistance from humans and are very rare and because of the rarity, they are very expensive. Cultured pearls are created when humans insert the irritant into the shell. Cultured pearls are grown on pearl farms where they are cared for while the pearl grows. Some pearls are started from an irritant type of nucleus, some, like the Akoya pearl, are formed around a bead nucleus. Only one out of four cultivated mollusks lives to grow a marketable pearl. Since natural pearls are so rare, it is safe to assume that most pearls on the market today are cultured. Pearls are among the softest gemstones on the market. On the Moh scale, they are only 2.5.
The most valuable pearls are perfectly symmetrical, fairly large and naturally produced. They have a shimmering iridescence which is called orient. I've listed a few of the more common terms used for 
pearls. Baroque pearls have an irregular shape. Biwa pearls are from the freshwater lake, Lake Biwa, in Japan and also have an irregular shape. Blister pearls grow attached to the inside of the shell. Freshwater pearls grow in freshwater mollusk and resemble puffed rice. Mabe pearls are cultivated blister pearls. Oriental pearl is another name for saltwater pearl.
Pearls are often enhanced by dyeing. They are very porous and accept dye well. It is the easiest, and least expensive way to get a matched strand. One drawback to this is that the dye can fade over time. They can also be bleached to increase their whiteness. Irradiation darkens the nucleus of the pearl to produce darker pearls like blue gray and black. Most experts believe this to be permanent. Metallic pearl colors are often both dyed and irradiated. As a general rule, all bright or striking pearl colors are dyed or enhanced in some way.
Pearls are found in Japan, China, Tahiti, Ceylon, Scotland, Norway, Australia, Indonesia, the Gulf of Mexico, and Myanmar. The finest Oriental Pearls are found in the Persian Gulf.
It is believed that Pearls help people see themselves, and eliminate emotional imbalances. They are also thought to give wisdom through experience. Ancient Chinese myths told of pearls falling from the sky when dragons thought. The ancient Greeks thought that pearls were the tears of the gods.

These photos are some of the Pearls I have in my gemstone stash.

 Faceted Pearls
 Keishi Pearls
Pale Pink Pearls