Natural australian opal is the birth stone for the month of October. The name is derived from Sanskrit word ‘Upalla’ which means precious stone, and yes Opal is a very prestigious stone, it is considered as a good luck gemstone. The internal structure of precious opal makes it diffract light. Depending on the conditions in which it is formed, it can take on many colors. Precious opal ranges from clear through white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. Of these hues, the black opals are the rarest, whereas white and greens are the most common. Opals vary in optical density from opaque to semi-transparent.
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