Black Star Sapphire Rough

Black star sapphires are black sapphires that display asterism.

Black star sapphire rough.

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. This effect is caused by asterism. Though this gemstone is black under the flashlight it will give the golden colour star effect on the surface. This effect is caused by asterism.

You can read more about asterism in our phenomenal gems article. Many people think that black star sapphires are an entirely different gemstone. 1280 cts 100 natural untreated unheated black star sapphire rough gemstone gemsbazarindia. 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.

Black sapphire pear 5 63 ct. Make offer 1240 cts 100 natural untreated unheated black star sapphire rough gemstone 32500 cts 6 500 kg 100 natural golden star sapphire rough loose gemstone 1 499 99. Although black sapphire is not a very popular or sought after gemstone this is not the case for black star sapphires. 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.

The inclusions are typically the mineral rutile but in black star sapphire it is inclusions of hematite that cause the star effect. This however is not true. Among all black star sapphire the most precious one is thai star sapphire. Black sapphire vs black star sapphire.

Star sapphires contain intersecting needle like inclusions that cause the appearance of a six rayed star shaped pattern. Black star sapphires owe their stars and their dark color to included crystals of the shiny mineral hematite. Black sapphire pear 5 63 ct. 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.

Sale price 104 93 104 93 149 90 original price 149 90 30 off. Clarity in star sapphires is a complicated issue. Tiny needles of silk within the sapphire crystal reflect light and form a star sapphire s telltale star. The most common star pattern is a 6 rayed star although star sapphires with 4 rays and 12 rays have been found.

This is one of the largest pieces of rough black star sapphire i have ever seen. A very large piece of rough black star sapphire.