12.00 ct Lovely Fancy Shape (22 x 15 mm) Multi Color Australian Koroit Boulder Opal Natural Loose Gemstone Rare Stone! Unheated / Untreated Multi Color Orgin From Australia 100% Natural Genuine Mined from Earth Gemstone!!! Gem Type Boulder Opal Color Multi ColorShape Fancy Size (LxWxD) 21.66 x 14.81 x 4.15 mm Weight 12.00 ct Hardness 6.5 Luster Excellent Clarity Translucent Treatment Unheated / Untreated Origin Australia RefractiveIndex 1.37-1.47 Specific Gravity 2.1 FL IF VVS1 VVS2 VS1 VS2 SI1 SI2 L1 L2 L3 L4 Flawless Internally Flawless Very Very Slightly Imperfect Very Slightly Imperfect Slightly Imperfect Imperfect Opaque Boulder Opal Mohs Hardness: 5.5-6.5 Found in Australia History: Opal is a semi-transparent solidified mineral composed of silicon and water. Boulder opal refers to a clear water opal with brilliant color play and a distinctive dark chocolate brown ironstone matrix. This opal was formed when silica-bearing steam was forced into cracks in ironstone boulders and then mineralized. The name opal is derived from the Latin opalus and Sanskrit upala meaning “precious stone”. The Greek term opallios translates "to see a change in color". The oldest known opal mine is in Czechoslovakia and dates to 14th century. Popularity of opal suffered in 19th century partially due to Sir Walter Scott's novel of a cursed stone and was thought to be bad luck. Queen Victoria promoted the stone in 1800s by giving opal jewelry to her children. In the middle ages, the stone was thought to make the wearer invisible, and was highly recommended to thieves. Today, Australia is major source for opal and supplies abt 85% of the world’s opal. It is a rather soft stone and needs care with handling. Do not immerse in hot water or a sonic cleaner. Opal is graded by size/cut/rarity/base color/fire color/fire intensity/fire pattern and fire consistency. Metaphysical: said to assist in recalling past incarnations, to develop psychic powers,bring out inner beauty, and draw money and luck Track Page Views WithAuctiva's Counter