The opals
THE OPALS
Opal is a mineral composed of hydrated silica with an average water content between 3 and 9%, but some varieties can have up to 20%. Black opal, especially that from Australia, is the most sought after and therefore the most expensive. Its name comes from the Sanskrit “upala” which means precious stone. Its structure is unique because it consists of tiny silicon balls arranged in pyramids irrigated by water veins. The refraction of light in this very particular structure gives play of light and colors so characteristic of this stone. It is considered that there are 2 categories of opals: one with play of color and the other without play. In the mines, the extraction of the rough stones in the veins is done mainly by hand. The vast majority of opals with color play come from Australia and also Ethiopia. On the other hand, opals without play of color come mainly from Brazil, Mexico, Peru and Tanzania. Opal is especially popular because of this shimmer of colors. These flashes of various colors change depending on the angle of view.
Black opal has a black background. The semi-black is rather gray. White opal has a milky white body color. The “welo” opal is the most sought after Ethiopian variety. It was discovered recently (2008) and is little known to the general public. Fire opal has no play of color but an impressive variety of tones in orange, red and even yellow, green or blue. As we can see the wide variety of opals makes it difficult to establish a common price grid for all. However, the price depends in particular on the shine, the intensity of the colors and the thickness of the stone.
Maintenance: having about 6% water, it is very important to take precautions. Do not use detergents, do not soak it in water, avoid leaving it in the sun, avoid thermal shock. If an opal remains in the water for a long time, there is nothing else but to wait for it to dry so that it regains its fires (iridescence) and its original colors. The drying time can last from a few hours to a few weeks. For long-term storage in a temperate place, you can place the opals in a cotton pouch moistened with a few drops of water. The pouch is placed in a hermetically sealed plastic bag. Opal is a relatively soft fragile stone so avoid shocks, especially do not tinker, play sports and shower with it.
Comments
No comment at this time!
Leave your comment