Black Star Sapphire Rough

Clarity in star sapphires is a complicated issue.

Black star sapphire rough.

Star sapphire is a type of sapphire displaying an optical star like effect. Star sapphire is a type of sapphire that exhibits a star like phenomenon known as asterism. Black star sapphires are black sapphires that display asterism. 1280 cts 100 natural untreated unheated black star sapphire rough gemstone gemsbazarindia.

Though this gemstone is black under the flashlight it will give the golden colour star effect on the surface. The most common star pattern is a 6 rayed star although star sapphires with 4 rays and 12 rays have been found. 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. A very large piece of rough black star sapphire.

Black sapphire pear 5 63 ct. You can read more about asterism in our phenomenal gems article. 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.

This effect is caused by asterism. This is one of the largest pieces of rough black star sapphire i have ever seen. 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. 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.

Tiny needles of silk within the sapphire crystal reflect light and form a star sapphire s telltale star. Many people think that black star sapphires are an entirely different gemstone. 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.

Sale price 104 93 104 93 149 90 original price 149 90 30 off. Among all black star sapphire the most precious one is thai star sapphire. 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. Black star sapphires owe their stars and their dark color to included crystals of the shiny mineral hematite.

This effect is caused by asterism. Star sapphires contain intersecting needle like inclusions that cause the appearance of a six rayed star shaped pattern.