Is opal expensive

Opal - precious shimmer

The word opal developed from the Latin and Greek term for precious stone and the Sank criterion upala, which means precious stone. Even the Romans and the ancient Greeks loved the beautiful mineral. Chemically designated with the formula SiO2nH2O, the opal has an amorphous crystal system. The colors of the stone range from colorless to red, yellow and blue. The gemstone is also often milky white. The line color is white and the Mohs hardness is 5.5 to 6.5. The opal has a density between 2.0 and 2.2 and its fracture is splintery and shell-like. As a gemstone, it is coveted because of the dazzling play of colors. This is especially the case with precious opals, and the iridescence is also often referred to as opalization. This phenomenon is caused by the interference and reflection of light in tiny spheres of silica gel.

The black opal is particularly valuable, as it amazes in the play of light and colors with interesting contrasts. There are locations for particularly noble opals in Australia, Mexico and the USA.

Value of opals: When assessing opals in terms of value, the determination of the size, basic color (black, semi-black, gray, yellow, blue, etc.), the pattern, i.e. colored spots (blue cheap, red expensive, multi-colored with red) is also valuable ), Color brilliance (matt, cloudy, slightly to strongly luminous, extremely luminous, brilliant) and transparency (Clarity Cross Test with 60 watt lamp) are important. The cut is also important. Asymmetry, inclusions, etc. to lead.