Kalyan Wiki
Gemstones
Gemstones are precious or semi-precious mineral stones used in making ornaments. These minerals need to be cut and well-polished to be used in jewellery. Some non-minerals like pearls and amber are also considered as gemstones. The uncut gemstones usually look like rocks; they are cut and polished to obtain the lustre that gives them their value.
Gemstones are classified into different types based on their colour, lustre, other physical properties, hardness etc. There is a wide range of semi precious gemstones available. However, precious gemstones are classified into just a few. The most commonly used precious gemstones are diamond, ruby, emerald and sapphire.
Diamonds: A diamond, made of carbon is the hardest natural substance available on earth. They are only found in very few locations around the globe. A diamond is considered as the world's most popular gemstone. An interesting fact is that diamonds are so hard that the tools used to cut diamonds are mostly made from the diamond itself.
Ruby: Rubies are formed from a mineral called corundum. They are red. Their colour can range from light red to slightly purplish red. The red colour is produced due to the presence of chromium. Heating the corundum under some particular conditions will help intensify its colour.
Sapphire: Sapphires are also varieties of corundum, which are typically blue. They are usually present in light blue and dark blue colours. These gemstones are used in both ornamental and non-ornamental applications. Other tones of sapphire include pink, purple, orange, yellow and green. There is a particular variety of sapphire available, known as 'star sapphire'.
Emerald: Emeralds are green in colour. They are formed from a mineral called beryl. Emeralds are usually found in sedimentary, igneous and metamorphic rocks. The green colour comes from the additional traces of vanadium and chromium. Their colour can range from bluish-green to yellowish-green.
Now let's take a look at the semi-precious gemstones. Almost all other gemstones other than the ones described above are considered as semi-precious gemstones. These include aquamarine, aventurine, chalcedony, amber, amethyst, chrysocolla, citrine, garnet, hematite, jade, jasper, lapis lazuli, malachite, moonstone, sunstone, tiger's eye, obsidian, onyx, peridot, rhodonite, tanzanite, topaz etc.
