QUOTE(Mambera @ 2008 01 26, 22:10)
R.Duda ir L.Rejl "Brangakmenių žinyne" oniksas net neišskiriamas atskirai, jis minimas prie kalcitų.
Cahlcedonai ir agatai priklauso tai pačiai kvarco grupei (SiO2), bet tai nėra tas pats.
prie kalcitu? ar turiu kito autoriaus brangakmeniu zinyna, ten yra oniksas priskiriamas chalcedono grupei. Lapuose ir turiu labai daug info-visur tai chalcedonas
kai kurie duomenys sutampa pvz. cia (versti labai tingiu
)
Onyx
Onyx is a striped, semiprecious variety of agate, with white, black, brown or red alternating bands. It is different from regular agate only in that the bands of which it is composed are parallel and regular. The name onyx originates from the Greek word onyx for fingernail or hoof, probably because of its weak transparency or possibly its color. Onyx may chip or scratch rather easily, so store it carefully. Onyx is one of the 12 stones mentioned in the Bible as adorning the breastplate of the high priests, and is also mentioned in Genesis 2:11,12: "
the gold of that land is good; there is bdellium and the onyx stone." The ancient Greeks and Romans used onyx for cameos and intaglios, and in India, onyx was worn for protecting against the evil eye and also for cooling ardor (it was believed that onyx provoked discord and separated lovers). In the Middle East, onyx was used as a worry stone because people believed the gemstone absorbed negative energy a belief that may have been produced by the Chinese miners who feared it and pulled the material out of the mine to immediately sell outside the country. Onyx is purported to help eliminate apathy, stress and neurological disorders, eliminate negative thinking, and sharpen the wits of the wearer. It is used to change habits, in addition to helping concentration levels and aiding absentmindedness. Some think it makes the wearer more eloquent, and thus it is worn for public speaking. The main sources of onyx are India and South America, but it is also found in China, Madagascar, Mexico and the U.S.A.
Black Onyx (-004)
Like nearly all black onyx on the market, ours has been rendered a uniform, permanent black color with a treatment by sugar and acid (and/or heat). This process has been used on the gemstone for thousands of years and is water safe. Black onyx is found worldwide but most commonly is from Brazil, India and Madagascar.
Blue Onyx (-012)
This gemstone, like most on the market, gets its bright, cheery color from a heating process. The color is water safe.
Green Onyx (-111)
Through heat treatment, this onyx has been colored a bright green and closely resembles the color of chrysoprase or jadeite jade. Green onyx is most likely water safe, but will probably fade over time. Most, if not all, green onyx on the market is enhanced to achieve its color.
White Onyx (-075)
White onyx occurs naturally, and unlike some bleached versions on the market, our current stock is unenhanced. However, this might vary depending on the raw material available.
ir cia idomu, kokie priklauso kalcitams
Hardness
6.5 - 7.0.
Occurrence
Worldwide. A member of the chalcedony family (micro-crystalline quartz).
Appearance
Onyx is the name given to chalcedony which is uniform in color, generally black or white.
Onyx should not be confused with onyx marble, a banded stone which is a form of limestone (calcite or aragonite).
Enhancements
Black and colored onyx is always dyed.
nerandu savo wordinio failo, ten ir turejau info apie oniksa, turiu daug internetiniu saltiniu, bet juos visus dabar perversti
Is patirties galiu sakyti, kad nera vienos tiesos apie akmenis, skirtingu saliu autoriu ir poziuriu informacija skiriasi