The chemical formula of Blue sapphire is aluminium oxide (Al 2 O3). The specific gravity ranges between 3.99 and 4.00 and the refractive index range is between 1.760-1.768 and 1.770-1.779. The hardness on the Mohs scale is 9. It is the next hardest mineral, diamond being the hardest.
Blue Sapphire (Neelam) Chemical composition
Blue Sapphire gemstone is made of Aluminum Oxide, Iron and Titanium
|Refractive Index||1.762-1.770 (+0.009/-0.005)|
|Specific gravity||4.00 (+ 0.10 /-0.05)|
|Melting point||2050 C (Approx)|
What Makes Blue Sapphire Gemstone So Fancy?
The beauty of Blue Sapphire, its magnificent colors, its transparency, also its constancy and durability are qualities associated with this gemstone by gemstone lovers and specialists alike. The sapphire belongs to the corundum group, the members of which are characterized by their excellent hardness (9 on the Mohs scale). Indeed their hardness is exceeded only by that of the diamond – and the diamond is the hardest mineral on Earth! Thanks to that hardness, sapphires are easy to look after, requiring no more than the usual care on the part of the wearer.
The gemstones in the corundum group consist of pure aluminum oxide which crystallized into wonderful gemstones a long time ago as a result of pressure and heat at a great depth. For centuries there were differences of opinion among the specialists as to which stones deserved to be called sapphires. Finally, it was agreed that the ruby-red ones, colored by chrome, should be called ‘rubies’ and all those which were not ruby-red ‘sapphires’. The presence of small amounts of other elements, especially iron and chrome, are responsible for the coloring, turning a crystal that was basically white into a blue, red, yellow, pink or greenish sapphire. However, this does not mean that every corundum is also a sapphire.
If there is talk of the sapphire, most gemstone aficionados think immediately of a velvety blue. It’s a versatile colour. A blue sapphire fits in best with a well balanced lifestyle in which reliability and temperament run together and there is always a readiness to encounter things new – as with the woman who wears it. In the trade, sapphires which are not blue are referred to as ‘fancies’. In order to make it easier to differentiate between them, they are referred to not only by their gemstone name but also by a description of their color. Fancy sapphires are pure individualism and are just made for lovers of individualistic colored stone jewelry. In other words, fancy sapphires are described as yellow, purple, pink, green or white sapphires. They are currently available in a positively enchanting variety of designs – as ring stones, necklace pendants or ear jewelry, as solitaires, strung elegantly together or as sparkling pavée.
However, the sapphire has yet more surprises in store. There are said to have been gemstone lovers who fell in love with these sapphire rarities for all time. For example there is an orange variety with a fine pink undertone which bears the poetic name ‘padparadscha’, which means something like ‘lotus flower’. The star sapphires are another rarity, half-dome-cut sapphires with a star like light effect which seems to glide across the surface of the stone when it is moved.