Black Star Sapphire Rough

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Black star sapphire rough.

Many people think that black star sapphires are an entirely different gemstone. As mentioned above it is rare that an exceptional rough star sapphire crystal isn t subjected to heat treatment to turn it into a more valuable transparent stone. Though this gemstone is black under the flashlight it will give the golden colour star effect on the surface. Tiny needles of silk within the sapphire crystal reflect light and form a star sapphire s telltale star.

You can read more about asterism in our phenomenal gems article. Black sapphire pear 5 63 ct. Among all black star sapphire the most precious one is thai star sapphire. Star sapphires contain intersecting needle like inclusions that cause the appearance of a six rayed star shaped pattern.

The most common star pattern is a 6 rayed star although star sapphires with 4 rays and 12 rays have been found. This however is not true. Star sapphire is a type of sapphire that exhibits a star like phenomenon known as asterism. It can take a lot longer to cut and shape a piece of this size into a cabochon because there is so much material to remove.

Although black sapphire is not a very popular or sought after gemstone this is not the case for black star sapphires. Star sapphire is a type of sapphire displaying an optical star like effect. Black sapphire pear 5 63 ct. Black sapphire vs black star sapphire.

The inclusions are typically the mineral rutile but in black star sapphire it is inclusions of hematite that cause the star effect. This gemstone has level of hardness 9 on the mohs scale which is similar or near to diamond thus this can be said it is the hardest substance next to diamond. A very large piece of rough black star sapphire. This effect is caused by asterism.

Clarity in star sapphires is a complicated issue. 1280 cts 100 natural untreated unheated black star sapphire rough gemstone gemsbazarindia. Black star sapphires are black sapphires that display asterism. Black star sapphires owe their stars and their dark color to included crystals of the shiny mineral hematite.

This effect is caused by asterism. Make offer 12x10 12mm x 10mm flat low dome oval black star sapphire cabochon cab gem es232 black star sapphire sri lanka natural genuine unheated gemstone gpg 677 2 100 00.