History and General Information on Natural Kyanite Gemstone

Natural Kyanite Gemstone, also referred to as Cyanite in ancient literature, derives its name from the Greek word ‘kyanos’, meaning blue. It can be found in aluminum rich metamorphic pegmatites or sedimentary rocks. The gemstone kyanite has other names like disthene and munkrudite that are associated with it. The white-grey kyanite is also known as 'rhaeticite'.

Due to its strong color resemblance to the beautiful deep blue sapphire, a good quality blue kyanite gemstone is often sold in the Indian market as the blue sapphire or ‘Kyanite-shani’. Kyanite is used primarily in refractory and ceramic products, including porcelain plumbing fixtures and dinnerware. It is also commonly used as a gemstone in fashion jewelry. Due to its similarity to the blue sapphire, the   natural kyanite is polished and set in silver or gold to make blue kyanite jewelry.

The blue kyanite crystal, or the blue kyanite beads lends itself well to creating fine jewelry with unique designs to form custom-made handcrafted rings, pendants, bracelets, necklaces and earrings.

Composition of Kyanite Gemstone

The chemical composition of natural kyanite is aluminum silicate (Al 2 SiO5). The specific gravity ranges from 3.56 to 3.67 and the refractive index range lies between 1.715 and 1.732. The hardness of on Mohs scale is 4 to 4.5 along the axes and 6 to 7 across the axes. The hardness of the kyanite gem stone changes with direction and this characteristic property gives this gem the name - disthene.

Physical Properties Of Kyanite Gemstone

Kyanite Color

The rough kyanite crystal  is usually blue in color. However, the kyanite gem can also be green, grey, dark grey, white, black and colorless as well. The color is not always consistent and intense throughout the crystal and often white streaks in a medium blue can be seen. The luster of the kyanite gem stone is vitreous to almost pearly.

The blue kyanite derives its color from the trace elements or minerals iron and titanium, similar to the ones that give the blue sapphire its color. The gem’s blue color is concentrated towards the centre and the gradation of color tends change to a colorless shade towards the edge of the stone. The green kyanite gets its color from the presence of vanadium. Colorless kyanite stones are quite a rarity in the market today.

Cut

Available in the cabochon cut (dome shape cut) and faceted into different cuts, the kyanite is not a very easy gem to cut. This is mainly due to the variation in hardness that is observed in different parts of the gem. The variance in the hardness is a significant characteristic that needs to be taken into consideration while the gem-cutter is cutting the gem.

Carat

kyanite gemsotne comes in various sizes and gemstones ranging from 0.10 carat to 5 carats in weight can be seen in the market.

Clarity

The luster of the kyanite ranges from vitreous to almost pearly. The common faint natural inclusions visible to the naked eye are minute needle-like inclusions, feathers and color zoning. These inclusions lead to the display of cats eye effect in  some kyanites. These catseye kyanites are usually bought as collector's gemstones.

Price, Cost and Buying of Kyanite Gemstone

The kyanite is not a very expensive gem and prices are generally low. Low quality stones are available in thef range of $5 to $20 per carat, while high grade gemstones may fetch a price of nearly US$50- US$75 per carat. While buying a kyanite, one should look for a uniform color spread, good luster and maximum transparency in the gem. Translucent and semi-transparent gems are relatively cheaper than completely transparent ones.

Where is Kyanite Gemstone Found ?

There is no one answer to the question – where is kyanite found. Kyanite deposits are found and mined in Austria, Brazil, India, Kenya, Myanmar, Serbia, Switzerland, USA and Zimbabwe. The green kyanite variety is found mainly in California, USA.

Simulants

By itself the blue kyanite gemstones are not a very popular gem. It is popular among jewelers due to its likeness to the blue sapphire. It is also marketed as the kyanite sapphire. The trade name enables the buyer to feel good that he has chosen a worthy substitute to the premium sapphire stone, which he may otherwise not be able to afford. The kyanite is a simulant of the blue sapphire. The simulants of the kyanite gemstone are Spinel, tanzanite and idocrase.

Interesting Trivia and other  Kyanite facts

The chemical composition of Kyanite is the same as two other gems - Andalusite and Fibrolite. However, these stones have a different crystal structure.

In ancient times it was believed that a kyanite suspended from a human hair could follow the earth's magnetic force like a compass needle. Travelers carried kyanite when they entered unknown territories to ensure a safe passage home.

The Kyanite is also believed to aid self-expression, communication and supernatural abilities.

Reference

1) Webster
2) Gemmology by Peter G.Read
3) Handbook of Gem Identification -   Richard  T.Liddicoat, jr
4) Gems and Crystals - From the American  Museum of Natural History - Anna S.Sofianides  and George E.Harlow.