October Birthstone Zodiac Sign The twelve Zodiac signs are an astrological version of birthstones in addition to the twelve calendar months. The October birthstone of the Opal is considered to be the birthstone for Libra (The sign of the Scales) and relate to those born between October 24 and November 22. The Zodiac sign of Libra also responds to Peridot, Agate Aquamarine, Tourmaline and Sapphire. October Birthstone - Where are Opals found? The popular October Gemstone of the Opal is found in the following countries: - Australia, Mexico and the U.S.
October Birthstone - the Color of the Opal The name opal actually means "to see a change in color." The opal occurs in several types of color. The White opal has a white body color with pastel glints of rainbow color. Black opal has a blue, gray or black body color. The black Boulder opal contains ironstone. Crystal or water opal is The transparent or colorless opal contains brilliant flashes of color within it. Fire opal is a transparent or a translucent opal with a yellow, orange or red body color that may also have a flash of color. Definition of the Opal, the October Birthstone Definition of Opal, the October birth stone: The word Opal is derived from the Latin word "opalus" which means "a stone". The precious opal presents a peculiar play of colors of delicate tints, and is highly esteemed as a gem. One kind, with a varied play of color in a reddish ground, is called the harlequin opal. The fire opal has colors like the red and yellow of flame. The Common opal has a milky appearance. Menilite is a brown impure variety, occurring in concretions at Menilmontant, near Paris. Other varieties are cacholong, girasol, hyalite, and geyserite. The crystal structure of the Opal (hydrous silicon dioxide), the October birthstone, is Amorphous. Opal miners restrict use of the term opal to precious opal, calling material that does not show a good play of colors, 'potch'. |