Onyx Fire Opal Tanzanite Necklaces in 14K Yellow Gold

Onyx is the birthstone for Leos and the anniversary gemstone for the 7th year of marriage. Black Onyx is the anniversary gemstone for the 10th year of marriage. Onyx is a variety of the microcrystalline quartz, called chalcedony. The name "chalcedony"" comes from Calcedon or Calchedon, an ancient port on the Sea of Marmara in Asia Minor. Ornamental materials were once mined in that area and it was an active center for trading various stones. Onyx were used widely in the past as bases and handles for gold items, as well as for stone inlay work. Onyx seals were very popular with the Romans, who carved the pattern of the seal in negative relief to give a raised point. They often used stones with several layers, each of a different color, which were then individually carved to produce a different pattern each year. They originally used the onyx name for a variety of marble having white and yellow veins. Onyx is the Greek word for ""claw"" or ""fingernail"" because these veins resemble the ... learn more

Mexican fire opals are named for their uniform flaming orange or cherry red body color. They are always very brightly colored, and can be a little bit cloudy to almost perfectly transparent. Transparent specimens have a good luster. Like the traditional opal, fire opals can occasionally display signs of iridescence in very bright light. Fire opals have a very low density, lower than that of glass, with which it is sometimes confused. Fire opals, like other opals, are relatively hard, rating a 5.5 to 6.5 on the hardness scale.... learn more

Tanzanite is a member of the mineral family zoisite, which has been known about for nearly two centuries. Zoisite occurs in a number of varieties, the most sought after being tanzanite. This mineral family was named zoisite in 1805, some time after the Austrian scientist Baron Siegmund Zois von Edelstein (1747-1819) had identified the mineral in the Saualpe Mountains of Carintha, Austria. Siegmund Zois von Edelstein operated an iron mine in the Karawanken Mountains in Karnten Austria and encountered the mineral on his own property. Centuries later, the discovery of a bright blue transparent variety that we now know as tanzanite, created a lot of excitement in the specialist world.... learn more