Sick Gems.

New Zealand Graphic, Volume XXIX, Issue VI, 9 August 1902, Page 381

Sick Gems.

Many people have an idea that precious stones are always iu the best of health. They make uo complaint, it is true, but too much sunshine and exposure to air will often damage them as much as it would the milk-and-roses complexion of a fair lady. Emeralds, rubies aud sapphires may be reckoned as hardy gems, but even they will lose colour if exposed to the air. Two rubies of the same size and shade were kept for a couple of years, one in a showcase and the other In a dark box. At the end of the two years they were compared, when it was discovered that the first had become lighter iu colour. topazes aud garnets are far more quickly affected by light. The garnet will become much paler in a short time, while the" topaz assumes a darker shade, and even loses the brilliancy it had when first cut. The most seusitive stone in this respect is the opal, which draws its marvellous rainbow reflections to numerous minute clefts that allow the light to pass and reflect it iu different directions. Often an opal will stand the process of cutting anil polishing well, and then some sudden change of temperature or other accident may cause it to split. Wearers of opal rings should, for this reason think twice before warming their hands at the fire.

Pearls very easily deteriorate. In the fire they rapidly become lime, pure and simple; and in vinegar or other acid they will dissolve.

Diamonds are less sensitive. Imt

is a wise precaul ion not to take Item too near the fire.