Tsavorite is a very modern gemstone, and it has two things in common with tanzanite: it too was found for the first time in East Africa in 1967, and was marketed by the Tiffany jewellery company of New York. Unlike tanzanite, tsavorite is a stunning green in colour, and is a member of the garnet family of gemstones, whereas tanzanite is blue and belongs to the zoisite family.

Why Tsavorite? The name is derived from the Tsavo National Park in Kenya, near the Tanzanian border, and the Tsavo River which flows through it. The gemstone was actually first found in Tanzania, but exploitation was not possible at that time. In 1971 it was found again, this time in Kenya, and mining could begin.

Tsavorite is prized by gemologists for its brilliant green colour, and its lack of inclusions. It has a similar hardness to emerald, being about 7.5 on the Mohs scale, and greater brilliance. It is a lot less expensive than emerald, but this is due largely to the greater rarity of emerald, and the lore of it’s long history. Indeed, tsavorite is a brilliant natural-green gemstone which has no need of enhancement as is the case with many other gemstones.

Tsavorite’s robustness makes it particularly hard-wearing when set in jewellery, and along with demantoid it is one of the most sought-after members of the garnet family. Sapphires and rubies may be harder then tsavorite according to the Mohs scale, but tsavorite, like all garnets, is extremely resistant to cracking, and in terms of a lack of inclusions is one of the most stable of gemstones. Like all garnets, it has a very high refractive index, and its sparkle surpasses the majority of gemstones, with the obvious exception of diamonds.

Unlike its geographical neighbour tanzanite, which often yields crystals in excess of five carats, tsavorite crystals tend to be smaller, and hence any tsavorite above two carats is likely to command a premium price. But whereas tanzanite is prized more for its colour than its brilliance, tsavorite has both beautiful colour and exceptional brilliance, and therefore is more desirable in the smaller sizes yielded by the rough tsavorite crystals.

Taking into consideration all of tsavorite’s qualities, such as its beautiful green colour, exceptional brilliance, excellent wearing qualities and relatively reasonable price, it is little wonder that it has become one of the most popular gemstones available today.

Peridot
Color: green, lime, yellowish green, olive green or medium dark green hues
Color of Streak: White
Moh’s hardness: 6.5 – 7
Density or Specific Gravity: 3.28-3.48
Cleavage: Indistinct
Chemical composition: (Mg, Fe)2SiO4
Refractive Index: 1.650 -1.703
Reflective Index: 31-37
Dispersion: 0.020 (0.012-.0.013)
Transparency: Transparent

Peridot: Introduction
The peridot is known as the official birthstone of August and the stone for the Zodiac sign of Libra. It is also the stone that is given on the 16th wedding anniversary. The color of the peridot comes in many shades of green, with just a hint of gold. Hence it’s Greek name ‘chrysolite’ meaning “golden stone” or the French word ‘peritot’ meaning “gold”. The peridot is one of the few gemstones that come in one color. It is also sometimes mistaken with emeralds and other green gemstones. This is why the peridot is often referred to as the “poor man’s emerald”.
For this newsletter we will be discussing more about the peridot.

Peridot: History
There were many instances in history where peridots were mistaken for other gemstones. As previously mentioned on the last newsletter on topaz, the peridot, which was mistaken to be topaz was mined on the island of Topazo off the Egyptian Red Sea. The peridots mined from the island were used to carve talismans and jewelry for Pharoah’s treasury. Egyptians worked tirelessly during the day as well as the night, when the gems could better be found due to the radiance which shines at night. This is why some call the peridot the “Evening emerald”. Another case of peridot being mistaken for another gemstone is Cleopatra whose favorite gemstone was the emerald but legends state that these so called emeralds were actually indeed peridot. One famous large peridot gem adorning the shrine of the Three Holy Kings in the cathedral at Cologne was for centuries, believed to be an emerald, and only recently to be identified as peridot late in the last century.

In ancient times the peridot was named the chrysolite. This name, chrysolite was also given to some colors of the topaz until further research was made in order to identify the difference between the two. In the middle ages, Europeans brought peridot stones back from the Crusades to decorate church plates and robes. Peridot was also known to ancient Hebrews and is listed both as one of the stones used by Aaron as the second gemstone used on his breastplate.

Peridot: How are they formed?
The peridot is formed from a form of magma from the upper mantle (20 – 55 miles deep), and are brought to the service by tectonic or volcanic activity where they are in extrusive igneous rocks. These rocks turn into olivine, which is a silicate mineral rich in magnesium and iron. Once the olivine crystallizes, it turns into gemstone form and forms peridot. This process usually takes long periods of time (usually millions of years) through high temperature and pressure within the rocks.

Peridot: Color
The peridot is one of the few stones that come in one color: green. Though it has only one color it can come in many different hues such as lime, yellow green, olive green, and medium dark green. The intensity and tint of the green however depends on how much iron is contained in the crystal structure, so the color of individual peridot gems can vary from yellow-green through olive green to brownish green. The most valuable is considered a dark-olive green color. The color of the peridot is the most important factor in determining its quality. Where emeralds have their own special green, which has perfect combination of yellow and blue hues, the peridot has its own special lime green color which makes it bright, lively and fresh.

Peridot: Cut
Most peridot cuts today are cut in a way that the stone is usually round or in an “emerald” cut. These cuts are usually made in the same region or area they were mined, usually in the south of Asia. A good cut of a peridot will be very noticeable to the eye because all facets are even and there are no windows in the stone where you can see through it.

Peridot: Clarity
Like all gemstones the peridot includes inclusions or internal “imperfections” which include either cracks or substances inside the gemstone which were made during the process of the gemstone’s formation. The most typical inclusion for the peridot is the “lillypad” inclusion, which are presence of biotite grains. The fewer the inclusions the higher the cost of the peridot will be. This is due to the fact that the less inclusions the more the peridot can “sparkle”.

Peridot: Carat
Peridots are not too rare and therefore are not that expensive. Small stones can be sold at about $5 per carat but if they do not have any inclusions they can be up to or under $50 per carat. Size does not play a big role in the cost compared to the previous C’s of the peridot but carat sizes of 8 carats or over depending on cut, clarity and color, can be worthy to display on a museum.