Magical minerals

By Sibel DORSAN

As old as the hills and as bright as the day, precious and semi-precious stones have a unique appeal to the human eye and the human imagination. They have become both a science and an art, and markets and myths have grown up around them. A few are also found in Turkey.

Precious and semi-precious stones and minerals have been used as ornaments since time immemorial. Formed through the precipitation and crystallisation of the crust of the earth under the influence of changes in temperature and pressure, they are to be found most commonly in the beds of streams, in fissures of rock, in mining facilities and in river valleys. Since these natural beds are scattered randomly around the globe, the discovery of these stones requires almost as much expertise as their processing. And it is only when the raw minerals are operated on, cut and treated, and used in the production of jewellery, that they take on their full value.

How precious is precious?

According to centuries-old tradition, diamonds, emeralds, sapphires and rubies are classed as precious stones. Other stones such as amber, topaz, amethyst, opal, agate, onyx, tourmaline, turquoise, quartz and jade fall into the category of semi-precious stones. Of course this classification is general and relative. While the value of one carat of high-quality jade can be worth thousands of dollars, the value of one carat of poor-quality diamond, sapphire or ruby can be less than a single dollar.

Stones are evaluated according to their beauty, their durability, the ease with which they can be cut and above all by their scarcity. Yet while scarcity is the crucial characteristic, there are limits to the value it commands. A stone so rare and unknown that no regular market can be created around it may have to be condemned to oblivion.

Small is beautiful

The beauty of a stone depends on its optic characteristics, its colour, its transparency, its brightness and its ability to break and reflecting light. Durability is the quality of being able to resist corrosion. These are natural characteristics. Learning to cut the stones takes much time, talent and practice, and it is the most important factor in determining the value of the final gem. This process requires that the optic characteristics of the stone be established beforehand, so that after surfacing, shaping and polishing, it will reflect the light in the most striking manner possible. 

Precious and semi-precious stones are generally small. Light and dazzling, they lend themselves well to insertion in gold and silver rings, bracelets, necklaces and ear-rings, so as to adorn the hands, arms, necks and ears of their fortunate owners. Over time, jewellers have come to use synthetic and imitation stones as inexpensive alternatives to the natural gems. But gemologists have little difficulty distinguishing authentic precious and semi-precious stones from their substitutes by their optic and physical characteristics as well as their peculiar chemical structures.

Mystical powers

The belief that stones have mystical meanings and powers is very widespread. Since ancient times, people have speculated that the stones have almost pharmaceutical powers to cure weak bodies and souls. Agate, a symbol of happiness and long life, is believed to be beneficial for stress, for example, while turquoise provides protection against the Evil Eye. Emeralds have been accepted as the symbol of eternal happiness, and are held to raise productive energy. Cornelian, the stone of good luck and abundance, supposedly provides for a long and healthy life. Many more such examples might be given. Topaz, which symbolizes true friendship, is credited with regulating the circulation of the blood. It is a widespread belief that Peridot helps to overcome phobias while Opal is regarded as the symbol of love and tenderness.

Turkish deposits

Precious stones have yet to be discovered in Turkey. However, a number of deposits of semi-precious stones have come to light. In Western Anatolia, black tourmaline, topaz and beryl have been identified in pegmatites in crystalline formations. Semi-precious stones with an economic value include amethyst - found in the Balıkesir and Giresun regions - and chalcedony in the region of Eskişehir. Agate has been extracted in Ankara, and tourmaline in Yozgat, while quartz is produced in the vicinity of Hakkari and Aydın, at either end of the country.

(DIPLOMAT  -  December 2004  -  Ankara)