OCTOBER BIRTHSTONE - OPAL

Opals are famous for their ‘play of colors’ – move the stones and you will find flash of colours of difference colours from the rainbow. The yellows and red colours found in Opals are due to the presence of iron oxides. Black Opals are very popular due to the red, yellow and green colours, caused by magnesium oxides and organic carbon in the stone. ‘Harlequin’ Opals are probably the most sought after, given this name because of the large angular patches of red, yellow and green resembling the checks on a clown’s costume.

The principal source of opals is Australia, noted for its magnificent black opals. Fire opals, a translucent to semi-opaque stone that is generally yellow to bright orange and sometimes nearly red were first mined in Mexico, and continue to be produced there today. In the United States, brilliant fire opals are also found in Nevada. Other commercial sources of opal are Brazil, Honduras, Nicaragua, Guatemala, Japan and Ireland. Peruvian opal, a blue-green stone found in Peru is also called blue opal.

The opal is a fragile hydrated soft stone, easily altered in appearance by changes in heat and pressure. This mineral contains varying amounts of water within it that determine the appearance of the gemstone. When water evaporates out of an opal, the stone appears slightly smaller and the stress of the evaporation can create cracks on it.

The opal has different meanings for different people; the ancient Romans thought that the opal was a symbol of love and hope; the Orientals called it the ‘anchor of hope’ but in Europe in the mid-14th century the Black Death swept across the continent, killing one quarter of its population. The opal was believed to be the cause of death. When worn by someone struck with the deadly plague, it would appear brilliant only until the person died. Then it would change in appearance, losing its luster. In reality, it was the sensitivity of this stone to changes in temperature that altered its appearance, as the heat from a burning fever gave way to the chill of death.