Monday, December 19, 2011

Tanzanite - Gemstone Of The 20th Century

Most gemstones have been known about for centuries, some for  millenia, so there is rich folk lore and tradition surrounding most of them.  The exception is Tanzanite, which was first discovered in 1967 near mount Kilimanjaro in Tanzania. It is the only place where the gemstone is found, and it is named after the country in Africa where it is found.

It was first marketed by Tiffany and Company in New York City.  It was first given the name blue zoisite as it is a variety of the mineral zoisite, but Tiffany changed it to Tanzanite because they thought it would help it sell better.  For ten years Tiffany had the exclusive rights to the stone, but in the 1970's the Tanzania government nationalized the mines.  Since the mines in Tanzania that produce the gem are nationalized, the government restricts the export of rough Tanzanite stones.  There are other entities that own parts of the mines and the supply of the gemstone is strictly controlled, thus the price has rose steadily over the years.

The color of Tanzanite can range from purple to blue. The rough stone is usually a reddish brown, and the rough stones are heat-treated to bring out the blue color. Almost all Tanzanite is heat treated at more than 900 degrees Farenheit and heat treatment has no affect on the value of the stone. The best quality stones range in color from ultramarine blue to sapphire blue with the most popular color being saturated blue which shows a purplish tint to it. It is a relatively soft stone,  and scratches more easily than many other gemstones. Care in wearing it and cleaning it is required.  In 2002 The American Gem Trade Association announced the Tanzanite has joined Turquoise and Blue Topaz as their birth stones for December.

Tanzanite has a rare property not found in most gems. When looked at in different light and at different angles it can appear to change color. From blue to violet to purple, some stones even show the colors dark red and gray. Tanzanite is usually clear with few inclusions. Stones with cracks or bubbles should be avoided as these could break.

Tanzanite is a beautiful stone, and considering it is found in only one 5-mile square place on earth, it is by its nature a rare gem that will only get rarer.  But it continues to be a popular stone, and has made its mark in the world of gemstones in a very short time.


Thursday, November 18, 2010

The Many Faces of Quartz

Quartz is the second most abundant mineral in the earth's crust. Pure quartz is colorless, but also occurs in many different colors, from clear to opaque A few examples of the many different kinds:
  • Purple quartz is called amethyst
  • Yellow quartz is called citrine
  • Black quartz is called onyx
  • Brown quartz is called smokey quartz
  • Agate
  • Tiger's Eye
  • Rose quartz
As quartz often occurs as crystals in nature, the ancients held it in high regard. The well-known crystal ball of the fortune teller of old was made from clear quartz. Ancient Romans thought the clear crystals were pieces of fossilized ice. The word crystal comes form the Greek word for ice.

No doubt because of its abundance and crystalline structure, quartz was known as having special properties in many cultures. Ancient Japanese thought that quartz was formed by the breath of a white dragon, and was a symbol of perfection. Indian culture believed quartz could detect food that had spoiled. Quartz played many roles in the rituals of Native Americans. It adorned the temples of the ancient Chinese. In the Middle Ages Christian relics were made from many different members of the quartz family, and like the ancient Greeks, they thought it was fossilized ice.

Rose quartz specifically has long been thought of as a love enhancer, and been highly prized for its mystical attributes. A stone that supposedly will give you improved self worth, and bring comfort to the broken hearted. It was even thought to help prevent wrinkles.

Quartz has also played a role in many scientific and technological advances. Crystals of quartz were used in the first radio transmitters and receivers. It has certain properties when an electrical current is passed through it and it is used in different kinds of meters and gauges. And quartz crystals played a major role in the development of the computer.

Most of the members of the quartz family are used to make jewelry of many types, and are in enough abundance that very nice, inexpensive jewelry is available. As well as higher priced items. No matter the color or type preferred, there is quartz jewelry to fit every taste and budget.


Amber - The Gemstone of Millennia

Gemstones of every color have attracted the eye of men (and women) since the dawn of time. Their attractiveness also made them items of great value. One of the oldest known of these 'pretty rocks' is also one of the few gemstones that have its origins as a substance from a plant. It began as resin that seeped from certain types of trees. A combination of pressure and chemical changes, the gemstone called amber was produced. Amber can be 45 million years old.

Pendants made from amber have been found that date back to 12,000 B.C.E. There have been quantities of amber found in the foundations of ancients buildings, leading to the speculation that it was placed there to ward off evil. Amber has been highly valued throughout history and was one of the first known commercial products. The demand  was so great that a trading route called The Amber Road developed that brought amber from the Baltic Sea all the way to Italy. This trading route lead to the possession of amber in many areas of the ancient world. Amber artifacts have been found in areas of ancient Greece, Egypt and England.

When the resin seeped from ancient trees so many million years go, sometimes it would trap various objects within it. These items are called inclusions, and can be a variety of insects, leaves, twigs, and other organic matter. These inclusions can contain insect and plant species that are no longer found on earth, and they add to the value of the stones.

Amber comes in many different colors such as orange, red, yellow, white, green, brown, blue and black (black is merely very dark shades of one of the other colors). It can also range in clarity from clear to cloudy. Seawater Amber, as its name implies, is found either floating in seawater or entangled in beds of seaweed.

The beaches and seaweed beds of the Baltic Sea was the greatest source of amber in the ancient world, and was the starting point for the original Amber Road. The stone is also mined on land, and is the greatest source of amber being used today, mined in this manner it is encrusted with other minerals and rocks, while sea amber has been polished smooth by water. Sea Amber is of greater value than the version found on land.

Much of the amber found today still comes from the Baltic Sea region of Eastern Europe and Russia, with many of the richest deposits found in Poland and Lithuania. Other major deposits are also found in The Dominican Republic and many different areas of Asia. Small localized areas of amber deposits have been found in The United States, with the largest U.S deposits being found in Arkansas.

The ancients credited amber with many magical properties. It gave the wearer strength, helped ward off evil, aided in healing, and enhanced the power of magicians, among others. The beauty of the stone still has the power to attract the human eye, and amber jewelry remains very popular. A thing of beauty is a joy forever, said the poet. In its many colors and forms, amber was a thing of beauty for the ancients. It remains a thing of beauty for us.


Wednesday, November 17, 2010

Cubic Zirconia - Too Perfect To Be A Diamond

The beginnings of cubic zirconia started when scientists were looking for less expensive material for use in lasers and optical equipment. Cubic zirconia appears in nature, but it is very rare and the crystals are too small to be of use. Scientists in France, and finally Soviet Russia found the breakthroughs that led to the methods of growing larger crystals in the laboratory. Production of the crystals began in 1976, and by 1980 world-wide production reached 50 million carats. It is used in the manufacture of optical components (prisms, lenses, etc.), insulators, medical instruments (scalpels) and jewelry.
  • The use of CZ (as it is usually abbreviated) in jewelry began almost immediately after it was being mass produced. It is similar to diamond, optically so close that only a trained eye can tell the difference. A comparison of the two substances:
  • On the Mohs scale of hardness, diamond is the hardest substance known with a rating of 10. CZ rates from 8.5 to 9.
  • CZ is virtually flawless, while even the best of diamonds have minor flaws.
  • Pure CZ is colorless. Only the most rare diamonds are colorless.
  • The facet shapes of CZ are different than diamond.
  • CZ is heavier than diamond. A CZ stone compared to the same size diamond weighs 1.7 times more.
  • CZ is one of the most efficient thermal insulators known, while diamond is one of the best thermal conductors. This difference is one of the tests to differentiate diamond from CZ.
Cubic zirconia is not only used as a simulated diamond but can be colored to match practically any gemstone in appearance A reputable seller of jewelry will always tell when CZ is used in jewelry and not try to pass it off as genuine diamond. It is a beautiful stone in its own right. It is less expensive than a diamond, and can give the wearer much pleasure, and at least a very good approximation of what an authentic diamond is. But the cubic zirconia's man-made perfect appearance tells the tale. In all things beautiful, there is nothing quite like the imperfect beauty created by nature. Beautiful and versatile it may be, but cubic zirconia is too perfect to be a diamond.


Marcasite - Pyrite in Disguise

Marcasite as the word is used in jewelry refers to small faceted stones that are inlaid in sterling silver. But the actual mineral marcasite cannot be used in jewelry as it tends to crumble into powder. Marcasite jewelry is actually jewelry using the mineral pyrite, sometimes referred to as iron pyrite.

Pyrite as it occurs in nature has a metallic luster, and can range from a very pale to a brassy yellow color according to the sulfur content. The yellow colored pyrite was mistaken for gold by inexperienced miners and earned the name fool's gold. These miners of years ago didn't realize it at the time, but pyrite can actually have very small amounts of gold in it. The sulfur content of the mineral has led pyrite to be used commercially for the production of sulfur dioxide used in the paper industry, and sulfuric acid for many industrial applications. Pyrite is found in many areas around the world

Pyrite used in jewelry is called marcasite. The name is derived from the Arabic word for pyrite, 'markaschatsa'. Evidence of this type of jewelry has been found in areas of ancient Greece and the burial grounds of the ancient Inca people of South America. It became very popular in the 18th century, reaching its zenith in the Victorian Era.

Marcasite is most often used with sterling silver. The darkness of it makes a good contrast to the brightness of silver. Gemstones are also used with it to good effect. Even when new, it has an antique look to it, and is used in Victorian Era jewelry reproductions. It is also used in many other kinds of jewelry. It can range in color from slightly brassy to pale green, but is mostly a dark metallic gray color.

From a simple marcasite and sterling silver ring, to ornate pendants with brightly colored gemstones, it is a very versatile material. This type of jewelry is found in very affordable jewelry right on up to very expensive. It has its own charm and beauty, this pyrite in disguise.




Tuesday, November 16, 2010

Black Hills Gold - America's Jewelry

In the 19th century, The Black Hills of South Dakota was an untamed area held sacred by The Sioux Native Americans. White men knew nothing about it when George Armstrong Custer led the first expeditionary force there in 1874. This expedition was a violation of a peace treaty with the Sioux, a violation that the Sioux never forgot. They exacted their revenge on Custer at The Battle Of Little Big Horn in Montana two years later.
A few months after the expedition had entered the area, a man name Horatio Ross discovered gold along French Creek. The lure of gold has the power to lure men to pursue it no matter where it may lead them. The gold found at French Creek had the same effect, and led to one of the last great gold rushes of the west. The town of Deadwood was a gold rush town, with all that goes with it. Prospectors, saloons, gambling, violence, and famous people. Wild Bill Hickok was shot to death in a saloon in Deadwood as he played poker. His card hand contained a pair of aces and a pair of eights, ever since known as the Dead Man's Hand.

The man that has been called the father of Black Hills Gold, S.T.Butler, also lived in Deadwood. His jewelry design of the colored leaf so often seen in this type of jewelry may have originated in San Francisco during the gold rush of 1849. Black Hills Gold designs also use grapes and grape stems as well as the leaves. The different colors used in the jewelry are alloys of gold. To obtain the green hue, silver is alloyed with yellow gold. Copper is alloyed with yellow gold in differing mixes to obtain red or pink gold.

While it is true that in the 1980's a federal judge ruled that any gold called Black Hills Gold must be manufactured in the Black Hills, this does not mean that the gold itself has to be from it. Makers purchase their gold from many sources, and as long as the jewelry is made, it is legal to use the name.

Black Hills gold begins with ingots of gold, silver and copper. These are melted and combined to make the different karat alloys used and different colors, then formed into gold bars. Some of these gold bars are then rolled to various thicknesses according to the needs of the jewelry being made, then they are stamped using patterns and dies. Other gold bars are used to cast the base of the piece of jewelry.

Cast pieces are polished, then the pressed gold items are hand soldered to the jewelry base. After further hand work, polishing and many inspections, a high quality piece of Black Hills Gold jewelry is the result. This type of jewelry is known for its high quality, beauty and value. It remains a popular type of jewelry that is not only very pleasing to the eye. It is a uniquely American form of the jeweler's art.


Mother Of Pearl - Opal Of The Sea

Mother of pearl is the iridescent substance called nacre, found on the inside of some mollusks. The word nacre comes from the Arab word naqqarah which means shell. It has been used for ornament, decoration and jewelry since 3000 B.C.E. Tombs have been discovered on the sites of ancient Mesopotamia in the Middle East that contained items made of mother of pearl. In some ancient cultures it was valued more than pearls. Before the 19th century, Japanese shell divers would discard any pearls found in the oysters they got, and keep the shell.

Ancient China also used mother of pearl for decorative inlay for various objects and jewelry. The Chinese powdered it and used it in medicines and prescribed it to lower blood pressure, as a cure for dizziness and as a heart medication. Native populations of South and North America also used mother of pearl for decoration and medicine.

In the Middle Ages in Europe, the main source of mother of pearl was the Persian Gulf. By the 16th century, this source had been depleted due to the huge demand. New sources were found in the Pacific. Areas in the Pacific such as The Solomon Islands and Tahiti were then plundered of their supply of nacre producing mollusks until the late 1880's when France gained control of Tahiti and restricted it. By the early 20th century the area was no longer a source of nacre.

In America, mother of pearl had been used mostly as an inlay for furniture until the 19th century saw it used for buttons. Muscatine, Iowa became the center of pearl button manufacture, and 'clammers' fished the Mississippi and other rivers for the nacre producing fresh water mussels. The buttons would be formed by punching out round pieces of the mussel shell. Billions of pearl buttons were manufactured, but they were very labor intensive to produce. By the beginning of World War II, the pearl button industry shifted to the production of plastic buttons as they were less expensive to make.

Mother of pearl continues to be used as decoration for many items such as furniture, musical instruments, and jewelry. Modern mother of pearl comes from fresh water and salt water sources in Europe, Asia, The United States, Japan and Asia. Mother of pearl that comes from abalone shell is some of the most valuable. With its iridescence and beauty, this opal of the sea is still in demand and highly valued.