Gems, in addition to Silver, Gold and Platinum, are the most valuable materials which are widely used in Jewellery. Any valuable or semi-valuable stones are called gems. The following are some expensive stones: Diamonds, Rubies, Sapphires, Pearls, Topaz and Emeralds.
Properties of Gems:
Diamonds are the hardest natural substance on earth. They come in many colours. Diamonds that are used (for jewels especially) are very clear. Diamond symbolizes strength. It is a stone of commitment and it can bring enlightenment. Diamonds are made out of carbon.
Rubies are the most vastly valued stones. Ruby is a Latin word which means red. They are known for their bright red colour that is called pigeon blood. Rubies represent passion and are stones of power. Production of natural rubies is lesser than that of artificial stones. Natural and artificial rubies are so similar that it is hard to differentiate between them.
Peridot are usually of an olive-green colour. They are very beautiful and refract light perfectly. They are becoming more and more famous these days. Peridot brings happiness and joy and is mostly known as the stone of cheerfulness. Peridot is an ancient gemstone. They are very rare and come in only one colour.
Sapphire is considered one of the most treasured of valuable stones. Sapphire is also a Latin word which means blue. Sapphire represents dignity. It is a stone of wisdom and strength. Sapphire’s colouring usually shows where it came from. They are the second hardest stones after diamonds.
Pearls have a variety of different colours, some of them are white, black, golden or pink. Mostly pearls are smooth and round, but they have other non-spherical shapes as well. Pearl represents patience, loyalty and thoughtfulness.
Topaz is a lustrous gemstone. Its colour is usually fiery-orange, but it comes in a variety of different colours as well. Topaz is an ideal gem. The most popular coloured topaz is pink, red, and a golden-orangish coloured. Topaz is also known as one of the clearest, cleanest and brightest coloured gemstone.
Garnet is a dark red coloured stone. It is crystal clear and its red shines beautifully. It is said that garnet was often used to illuminate dark rooms like arks, in ancient times. It is a popular gemstone these days. The colour of garnet is similar to a pomegranate. There are more similar species of garnet that have similar crystal forms and properties.
Emerald gemstone is a mixture of blue and green and adds to the variety of beryl, which is a mineral species that includes aquamarine. They are known for their beauty and value. Emerald represents happy new beginnings. It is a stone of hope and rebirth. Emerald is a valuable stone used since very ancient times.
Setting, Cutting and Engraving of Gems:
Stone engraving was probably the first ancient technique which used to produce seals. Gemstones are first cut and polished for their use in Jewellery.
In crown settings, the rim is first shaped into metal tines and then the metal tines are hammered down on the gem, in order to hold the gem in place.
As the cuttings advanced for stones, setting techniques also advanced. The target was to leave the stones as noticeable as possible (especially in necklaces and bracelets).
Pearls, in ancient classical times were sliced with a drill. Whether the pearls were to be threaded on a necklace or attached onto a jewel, the hole (made by the drill) went half or all the way over.
By using artificial methods and different techniques, the colour of gemstones can be changed. The use of sugar, dyes and heat can also change its colour. Alexandrite, Garnet, Sapphire, Diaspore, Andesine and Fluorite are some of the colour changing gems.