Moonstone is known to exhibit a distinct sheen under certain lighting conditions, and it is the sheen which renders moonstone one of the most remarkable gemstones available today. In fact, its name is owed to the almost magical, bluish white shimmer it exhibits, which closely resembles that of the moon. Gemologists refer to the shimmering optical phenomena as 'adularescence'.Moonstone is typically colorless, but it can occur in a wide range of colors, including gray, mocha brown, yellow, orange, green, pink, blue and white. It most often exhibits a white to bluish-white sheen, but other sheens can occur such as silvery and blue-orange. Sri Lanka's moonstones with a pale blue sheen on a near-transparent body are considered most valuable. India's moonstones show cloudlike plays of light and color which are very valuable including beige brown, green, orange or simple brown. Rarer colors include blue, peach, smoke, champagne, black and red.Moonstone typically occurs with translucent clarity. Transparent specimens are uncommon, but not unheard of. Transparent moonstone is considered most valuable. Moonstone has an attractive vitreous to pearly luster when cut and polished.India is known for producing fine 'rainbow moonstone'.