Corundum
Corundum is a crystalline form of aluminium oxide with traces of iron, titanium and chromium. It is a rock-forming mineral. Corundum is the second hardest natural mineral known to science. The hardest mineral, diamond is still four times harder than corundum. The hardness of corundum can be partially attributed to the strong and short oxygen-aluminum bonds.
The name “corundum” is derived from the Tamil word “kuruntam” meaning “ruby”, it is derived from the Sanskrit “kuruvinda”.
Corundum is rare gem and has crystal lining in their atomic structure. When these are taken nearer to the light, these look like sparkling starts. Star sapphires should be used to render proper guidance and should be minimum 3 carats. The purer variety of corundum is colorless.
The most important of the gem families, corundum provides us with two of the best-known stones: ruby and sapphire. The popularity and price of these gemstones remain strong due to the beauty, durability and versatility of the material. Unfortunately, however, the ongoing development of synthetics, imitations and enhancement treatments has made the task of choosing and buying sapphire or ruby complex and sometimes risky.