Spodumene Gemstones - Hiddenite, Kunzite & Triphane
Introduction
The name Spodumene may seem like an unlike name for a family of gemstones from which the wonderful gemstones kunzite and Hiddenite come from. The name Spodumene is derived from the Greek word Spodumenos, which means "burnt to ashes". This name was developed since many types of Spodumene had a strong resemblance to brunt ash, due to their grey color. All the Spodumene gemstones have a high pleochroic nature.
Spodumene in itself, is rarely set in jewelry, but its three descendants, namely Hiddenite, Kunzite, and the recently discovered Triphane are some of the most desirable gemstones in the world. Triphane is usually confides with the sleeping agent known as Tryptophan, which can be found in high levels in turkey meat, and this is probably the reason why many people fall asleep on Christmas after eating the meat for dinner.
Spodumene is classified as a pyroxene material which consists of lithium aluminum inosilicate, and is used in industry as a source of lithium. This is a mineral that is found in lilac, purple and yellow kunzite, the emerald green hiddenite and is found in large prismatic crystals. In Dakota, crystal sizes measuring up to 14.3 meters have been found in the Black Hills.
The discovery and occurrence of Spodumene
This is a gemstone that was found in Uto Sodermanland, in Sweden in the year 1800. The Brazilian naturist Jose Bonifacio de Andrada e Silva is the one credited with this discovery.
This is a mineral that is found in granite pegmatite and aplite that is rich in lithium, and is associated with minerals such as lepidolite, beryl, eucryptite, albite, petalite and quartz. The Spodumene varieties that have a strong transparency have long been used by gemstone connoisseurs in the making of jewelry, and these are kunzite and hiddenite, both of which have a strong pleochroic character. Spodumene is found in Brazil, Madagascar, Afghanistan, Australia, Canada and North Carolina.
The economic importance of Spodumene gemstones
Spodumene is primarily used in the extraction of lithium, which is then used in making ceramic items, batteries for cars and mobile phones, and in medicine as a fluxing agent. The lithium is extracted from this mineral by fusing the Spodumene with acid. Global production of lithium from Spodumene is estimated to be about 80,000 metric tons, every year. The Spodumene that is primarily used for this purpose comes from the Greenbushes pegmatite, which is found in Western Australia, and also some from Chinese and Chilean mines. In GreenBushes, the Talison mine has been declared as having more that 13 million tons of the mineral in its deposits.
There are certain people who claim that Spodumene with no longer be an important source for lithium, since there is an alkaline brine solution that comes from lakes in Argentina, China and Chile, from which lithium chloride can be directly extracted. The lithium chloride is then converted into lithium hydroxide and lithium carbonate by reacting it with calcium hydroxide and sodium carbonate respectively.
Now, these experts may be wrong about the declining importance of Spodumene as a source of lithium, because it is much easier and faster to move the minerals from the miens and into the production plants, than it is to move the brine from the lakes. It can take about one and a half to three years to completely evaporate the water, in order to get the lithium chloride from the brine, while the mills that convert the Spodumene will give out lithium in as little as three days.
There is another important factor which makes for the support of getting lithium from Spodumene; the lithium extracted from the mineral is much purer that that which is produced from the brine solutions. The lithium that is used in making batteries for cars and mobile phones must have a purity of lithium carbonate of 99.5 percent. The remaining 0.5 percent must have a certain makeup, because high amounts of iron, magnesium and other deleterious materials, such as those found in the brine solutions, will make the product less attractive for this purpose.
The gemstone varieties of Spodumene gemstones
As seen before, most Spodumene is used for the industrial extraction of lithium, but there are those varieties which are used for the making of gemstone quality minerals.
Hiddenite
This is a pale Spodumene that can be described as being a light emerald green, and it was first found in Alexander County, in North Carolina, United States of America. The green color found in this Spodumene is due to the presence of chromium, much like what happens in emeralds. However one must note that not all green Spodumene has chromium, and these tend to have a light green color and cannot be properly assigned the name hiddenite.
Kunzite
This is a Spodumene variety that has colors ranging from pink to lilac, and this color is due to the presence of minute amounts of manganese. There are some kunzite stones, but not all, which can have this color enhanced by treating it with heat. Usually, all the kunzite stones used for jewelry are treated with irradiation in order to enhance the color. When they are exposed to sunlight, kunzite gemstones lose their color, but irradiation restores it.
In 1902, the chief jeweler at Tiffany & Co, known as George Frederick Kunz, discovered the stone as he was on an expedition, since he was also a world renowned mineralogist. Today, this mineral is found in the United States of America, Canada, Brazil, Mexico, CIS, Western Australia, Sweden, Pakistan and Afghanistan.
The Russian Plamette Tiara and Necklace, which were worn by the Duchess of Gloucester, are some of the most notable kunzite jewels in the world today.
A closer look at hiddenite
The green variety of Spodumene is known as hiddenite. Spodumene is a mineral that can be found in many places on the planet but it is only in a handful of places where you can find hiddenite, which is the transparent, greenish form of this mineral. Of the two Spodumene varieties that are used in the making of jewelry, hiddenite and kunzite, hiddenite is much rarer. Hiddenite is a gemstone named after William Earl Hidden, who played a major role in the classification and description of this gemstone. In North Carolina, the town where the first deposit of this gemstone was found, has been aptly christened hidden, in honor of the fact that it brought forth the beauty of the stone to the world.
The chemical and physical properties of hiddenite
The chemical formula of hiddenite is LiAlSi2O6, which makes it a Lithium-Aluminum-silicate. It has a predominantly green color, and has a hardness of 6.5 to 7 on the Mohs scale. It has a monoclinic crystal structure and a refractive index of 1.66 to 1.68. The gemstone has a specific gravity of 3.1 to 3.2 and can be classified as a transparent gemstone. It has a double refraction of 0.015, and a vitreous luster. It has a cleavage of 1.2 along the prismatic axis.
More about hiddenite
It was in the year 1879 that hiddenite was first found; in the strictest of terms, this mineral was defined as a green, transparent variety of Spodumene which was rich in chromium, and was found in North Carolina. Ever since, there have been other areas in the world where hiddenite has been discovered, but their significance pales when they are compared to those that were brought from North Carolina. It is the chromium impurities in the crystals which are the cause of the emerald green color of the hiddenite which is sourced from North Carolina. Other localities produce hiddenite that has lower levels of chromium or none at all, and they have a light green color, or are sometimes yellow.
In the strictest sense, the name hiddenite should only be used on the Spodumene variety mined by the Alexander Co,. which is located in North Carolina, since this is the perfect green transparent variety. However, there have been other deposits that have been found in Afghanistan and Brazil, which are also green in color, but do not deserve to be given this name. The name has been corrupted to include the Spodumene from these other locations amongst many others. The natural and original hiddenite that comes from North Carolina has become rarer as the years have gone by.
Hiddenite has a perfect cleavage and a fracture that is very splintery, and this makes it quite a challenge to fashion into a faceted gemstone. If the stone is hit too hard, it will chip off, since it is very sensitive to hard knocks. Hiddenite also has a very strong pleochroic character, and it shows lighter and more intense colors when it is viewed from different angles. There are hiddenite varieties that have more than one color in a single crystal, with yellow tones are one end and green ones at the other. It is also possible to get hiddenite stones that have a very deep green on one side, and the other side being almost colorless. Generally, the value of hiddenite increases as the green color intensifies; the uniformity of the color also affect the value.
Just like Kunzite, Hiddenite is also sensitive to periods of extended exposure to sunlight and the color fades; the same also happens when it is exposed to bright light. It is also possible to create artificial hiddenite by exposing other Spodumene forms to irradiation, and it is also difficult to tell the difference with natural forms. When buying hiddenite jewelry or gemstones, one should be very careful, and only visit well known and respected dealers and jewelers.
Hiddenite is used mainly as a connoisseur gemstone, and getting good gems is very hard; these rare forms are very expensive and they can also make unique jewelry pieces. Hiddenite is also called the Lithia Emerald
A closer look at kunzite gems
Kunzite is the other variety of mineral Spodumene which has a pinkish to light purple color. It is very rare that you find these clear, colored Spodumene samples despite the fact that Spodumene is a very common mineral in the world. Kunzite is the main gem form of Spodumene, and is slightly more abundant than its counterpart, hiddenite. One can also find yellowed and colorless forms of Spodumene, but they have only been recently discovered and are not well known. The lovely pink and purple colors of kunzite is making it become very popular with women.
The chemical and physical properties of kunzite gemstones
Kunzite also has the same chemical formula as hiddenite, and this means that it is a Lithium-Aluminum-Silicate; the formula is written as LiAlSi2O6. The color of kunzite is mainly pink, but you will find some that can only be described as being light purple in color. Kunzite has a hardness of 6.5 to 7, and has a monoclinic crystal system, with a refractive index of between 1.66 and 1.68. This wonderful gemstone has a specific gravity of between 3.1 and 3.2. This can be classified as a transparent mineral and is therefore ideal for the creation of jewelry. It has a double refraction of 0.015 and has a vitreous luster. It has a cleavage of 1.2 along the prismatic axis.
More about kunzite
Kunzite is a gemstone that can only be termed as being relatively young, when compared to other valuable gemstones. It was discovered in the 20th century, in the pegmatite deposits found in Pala, California. To be more precise, this gemstone was discovered in 1902, and was named after the famous naturist and mineralogist known as George Frederick Kunz, who is the first person to identify the gemstone. After this period, kunzite was usually found in collections and not as jewelry, until the 1990s when people, especially women, started preferring it as a piece of their jewelry.
Despite the fact that kunzite is a very attractive gemstone, it is known for having a bad habit of fading when it is exposed to bright light or sunlight for extended periods. The fading of the color is very slow, and the wearer may not notice it until after several years. It is best advised that kunzite jewelry be worn only during the night, for dinner parties and nighttime dates, amongst many social functions that take place at night.
Kunzite deposits are quite well-spread, and the mines produce huge quantities of the gemstone making it quite affordable. It is also possible to get large and flawless kunzite crystals, and these are used to make very large and faceted gemstones for collections and jewelry.
Kunzite is a gemstone, which unfortunately, has a perfect cleavage, and a very splintery fracture; this feature makes it very difficult to facet into a gemstone. This is one gemstone that does not react well to hard knock and will chip if it is struck too hard. Kunzite, just like hiddenite, has a very strong pleochroic nature, and shows intense and lighter colors as it is viewed from different angles. This is the reason why it must be cut by an experienced lapidary, who knows how to align the stone so that the deep pink color is seen from the top of the gemstone. The more intense the pink color of kunzite is, the more expensive the gemstone will be.
Kunzite is a very delicate gemstone, and its soft nature makes it embody the nature of a lady. This is perhaps another reason why the stone is so popular with the ladies. It is not possible to cut small gemstones from kunzite, since the strong pleochroism and delicate nature of the stone will make them easy to break, and the pink color may not be apparent due to the pleochroic display. This is a gemstone that does well when made into pendants and as ornamental stones on other objects, since the large size required to bring out its best qualities, suit these kinds of uses. The use of kunzite in rings and necklaces is very rare because these items require that the stones be cut into small pieces. The less transparent kunzite gemstones are cut into beads and cabochons.
There are other varieties of kunzite, and these are:
- Yellow kunzite · which is transparent and yellow-colored.
- Blue kunzite · which has colors that range from light blue to bluish green.
- Rose kunzite · this is a synthetic pink sapphire and the name is erroneously give to the gemstone.
Most kunzite is very light in color when in its natural form; the gemstone is treated using heat in order to intensify the pink color and also remove any impurities that gibe it brown blotches. Kunzite is found in many countries and some of the notable ones are Pakistan, Afghanistan, Madagascar, the United States of America, notably in California and Maine, and finally Mozambique.
