Tanzanite Clarity: How to Choose this Rare Stone
If your heart is set on a beautiful blue or violet tanzanite, you've likely wondered how to choose the best stone for your budget. Tanzanite may be considered rare, but stores have plenty of tanzanite jewelry to choose from. So, how do you pick the best tanzanite stone? We've created a quick, essential guide on tanzanite clarity to help you learn more about one of the most important considerations when choosing a tanzanite gem.
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Gemstone Clarity
There are a few considerations when selecting a gemstone, like Tanzanite. Other than tanzanite color, you'll want to focus on tanzanite clarity.
Gemstone clarity generally refers to how many flaws or inclusions a stone has. Stones with inclusions have lower clarity grades because they are less "clear" than others. Diamonds receive similar clarity ratings. Although, diamonds are graded more harshly because even the most minor blemishes can detract from this colorless, sparkling stone. As you can imagine, the higher the clarity rating a diamond receives, the more its price increases.
But what about colorful gemstones? Well, they're a bit different. In most cases, their grading is less strict, and visible inclusions may not affect the price significantly. However, this can depend on the type of gemstone. Stones known for inclusions include tourmalines and emeralds, while aquamarine, Tanzanite, and Morganite have very few inclusions.
Clarity and Tanzanite Value
Thankfully, Tanzanite is classified as a Type 1 stone by the GIA. Type 1 stones are relatively free from inclusions and generally have good clarity. They are known as "eye clean" in the jewelry business. Eye clean means you cannot see any inclusions or blemishes when viewed with the naked eye (or without magnification). In most cases, jewelers will take raw Tanzanite and cut away many of the inclusions, as long as it isn't detrimental to the gem.
The final product, a beautifully eye-clean stone, can be made into a tanzanite ring, tanzanite earrings, or some other piece of jewelry.
Out of all the "eye-clean" tanzanite stones, those with a vibrant blue hue are often the most sought after. Violet or purple tanzanite stones are slightly less valuable but still beautiful. Deep blue stones often undergo heat treatment to enhance their color. Nearly all Tanzanite starts as a brown color and only becomes blue or purple through heat treatment. Natural blue or purple are exceptionally rare.
Rich blue Tanzanite may mask inclusions more easily, while a pale purple or blue stone can have a more challenging time being deemed "eye clean ." It's important to remember that while a deep or vivid blue stone may have more inclusions than a lighter stone, it could still be more valuable. Tanzanite's value in regards to clarity is how clean the stone looks, not how clean it truly is.
What if Tanzanite has lots of inclusions? Though there aren't many Tanzanites with numerous inclusions, meaning those with low clarity grades, may be made into beads or cabochons. A cabochon is when a stone is cut and polished into a domed shape with a flat back and a rounded surface. These stones can also be set in jewelry.
Types of Tanzanite Inclusions
When determining if Tanzanite is eye clean, what are gemologists actually looking for? Different types of inclusions can affect Tanzanite. Some of them provide interest to a stone, even if they do make it unsuitable for Tanzanite engagement rings or tanzanite necklaces.
Feathers
In most cases, these inclusions appear to be "feather-like ." They're the easiest to spot in clear Tanzanite and can be millimeters long. Feathers can be caused by crystal growth, fractures, or liquid. They're usually not opaque and still allow light to pass through the stone without making it look hazy if they're small in number. Fluid inclusions can signal that the Tanzanite has never been heat treated.
Needles
Sometimes known as tubes, these pillars can be delicate or large in size. They intersect and form a pattern in some cases, while others occur alone. Sometimes, needles can create a striking design on the stone that is ideal for display in a cabochon.
Included Crystals
Smaller crystals result from one growing tanzanite meeting another compound when it is forming. In some cases, Tanzanite will grow around another material. Standard inclusions include graphite, actinolite, calcite, and diopside. Occasionally, merelaniite can be found inside Tanzanite, creating whisker inclusions rather than crystal clusters.
Tanzanite Clarity Scale
The Tanzanite Foundation recognizes the following grades: Eye Clean (EC), Slightly Included (SI), Moderately Included (MI), and Heavily Included. In addition, the GIA recognizes stones in regards to clarity as Type 1 (generally eye clean), Type 2 (often contain inclusions), and Type 3 (often have numerous conclusions). As a Type 1, Tanzanite's clarity is graded more harshly by the GIA using the following ratings:
- VVS: very, very, small inclusions
- VS: very small inclusions
- SI1 & SI2: small inclusions
- I1, I2, & I3: included
Though the GIA often deems VVS stones as internally flawless, most gemstones are not. A VVS Tanzanite will be eye clean, sometimes even up to 10x magnification.
Other colored gems are graded on a scale ranging from AAAA to B. Those rated AAAA, the highest rating, are deemed eye clean, rich in color, and free from artificial treatment. AAA will possess similar clarity, although usually obtained through treatment. Treatment doesn't hurt or degrade the stone; it only enhances its beauty.
Lower grades often have some slight, visible inclusion(s). Natural AAAA Tanzanite can be incredibly rare and valuable. As Tanzanite only comes from a single source in the world, fine quality tanzanite gems are becoming increasingly hard to come by.
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