Maxixe (pronounced "mashish") is a rare variety of beryl with a dark blue color. This information is important to many buyers - even to buyers of low-cost items. The color improvements achieved by heat treatment are thought to be permanent and undetectable by current methods of testing.Īny time a gem has been heated, irradiated, dyed, or undergone other treatments to improve its color, durability or appearance, the seller should disclose that information to the buyer. Most of the aquamarine offered for sale in today's market has received heat treatment. Greenish yellow and other colors of beryl can be altered to colors within the aquamarine range by heat treatment. Gentle heat treatment can remove the yellow color and transform the gem's color to a more pure and more valuable blue. Most natural aquamarine has a greenish blue color. Ferrous iron (Fe 2+) is responsible for blue color, and ferric iron (Fe 3+) is responsible for yellow color (which combines with the blue color to produce greenish blue). The iron can occur in two oxidation states. The greenish blue to blue color of aquamarine is caused by trace amounts of iron.
Aquamarine Color and TreatmentĪs a member of the beryl mineral family, aquamarine has a chemical composition of Be 3Al 2Si 6O 18. Heat-Treated Aquamarine: The blue color of this 0.52-carat faceted aquamarine from Madagascar was improved by heat treatment.
It can be difficult to find a small gem with a rich blue color, but as the size of the stone increases, the opportunity to find strong color also increases. As the size of the gem increases, the strength of its apparent color will also increase. Size: Aquamarine is available in a wide range of sizes. A small aquamarine with a rich blue color will cost a lot more than identical-size stones with a faint blue color. Gems with a rich blue color are much more expensive because rich color in aquamarine is very rare. Gems with a faint blue color are abundant and inexpensive. A mounting that guards the stone from impact and not wearing the gem during activities that might result in accidental impact are important precautions.Ĭolor: The price of aquamarine is mainly determined by weight and the strength of its color. However, aquamarine's tenacity is rated as brittle - which means that the gem can be easily chipped upon impact.
Hardness is a property that enables a gem to resist scratching. Diamond, ruby, sapphire, topaz, and chrysoberyl are the only popular gemstones that are significantly harder. If you are interested in purchasing an item of aquamarine jewelry, here are a few things to consider:ĭurability: Aquamarine has a Mohs hardness of 7.5 to 8, making it one of the harder gemstones. Hexagonal (often occurs in prismatic to tabular crystals with a hexagonal cross section)Īquamarine has a hardness and durability that makes it suitable for all jewelry uses.Īquamarine is such a popular gemstone that it can be found in almost any jewelry store in the United States. Hardness and relatively low specific gravity. If it is used in a ring, bracelet, or other impact-likely item of jewelry, a design that guards the stone should be used.Greenish blue to blue (color almost always has been improved by heat treatment)Ĭrystals are prismatic, often with flat terminations, hexagonal, and without striations. Tanzanite is best used in earrings, pendants, and pins, where abrasion and impact are unlikely. Sapphire has a Mohs hardness of 9, while tanzanite has a hardness of about 6.5. For those reasons, tanzanite has become a lower-cost alternative to sapphire. It costs much less than sapphire, but is every bit as attractive - some people even prefer tanzanite over sapphire. In the United States, tanzanite is the second most popular blue faceted gem after sapphire. Tanzanite's wonderful blue color and Tiffany's promotion quickly made it an extremely popular gem. Tanzanite is a relatively new gem, first discovered in the 1960s, whereas most other popular gems have been known and used for hundreds, if not thousands, of years. Tiffany and Company selected the name to honor the country where it is produced. Tanzanite is a violetish blue gem that is only found in commercial amounts in the African nation of Tanzania.
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