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Quartz is a crystalline rock or mineral composed of silicon dioxide. It is the second most common mineral on the Earth's continental crust and is found in all types of geological environment. There are forty-nine varieties, a number of which are gemstones, some of which are very beautiful and very ...
Jasper is a micro crystalline quartz, made from very small grains. It is semi-translucent to opaque. Jasper has been used for thousands of years as tools and weapons during pre-historic times and later for ornaments and jewellery. The origin of the name is the Greek word "iaspis". Jasper is ...
Turquoise is composed of aluminium phosphate and copper. Its name originates from the French word for Turkish stone, as in ancient days it was transported through Turkey. It was very popular in Ancient Egypt and Ancient Persia, and known to man since at least 6,000 BC. Delicate veining, caused by ...
Tourmaline is one on the most complex gemstones of the silicate group. There are ten different varieties created by the dozen or more elements they contain. The origin of the term is the Sinhalese word "turamali", meaning stone of mixed colours. There are tourmalines, which change colour from ...
Topaz is a fluorosilicate and can contain trace elements that cause different colours within the gemstone. Its name originates from the Greek word "topazion", a Red Sea Island often covered in mist. In the Middle Ages the name topaz was used to refer to any yellow gemstone. Deposits of topaz are ...
Sapphire is any colour of the mineral corundum other than red, which is called ruby. Corundum is composed of aluminium oxide. Sapphires tend to be translucent or transparent and have high amounts of refraction. The most desirable sapphires are generally those with an intense blue colour with plenty ...
Red variety of the mineral Corundum, which is composed of aluminium oxide. The red colour is caused mainly by chromium and titanium. It is natural for rubies to have imperfections, including colour impurities. The origin of the name comes from the Latin word "ruber" for red. Natural occurring ...
It is the gem variety of the mineral olivine. The origin of its name is either the Arabic word "faridat" meaning "gem" or the French word "peritot" meaning "unclear". Peridot is one of the few gemstones that come in only one colour. The depth of green depends on how much iron is contained in the ...
