SAPPHIRE
Sapphires belong to the corundum family. Blue sapphires are the blue variety of it. The name corundum is Indian in origin, derived from the Sanskrit "kuruvinda," Hindi "kurund," and Tamil "kundundam," and translates to "hard stones."
Sapphire, Madagascar (2.04 ct)
Class: oxides
Genesis: metamorphic, and magma; the best quality is derived from marble
Colors: blue – further important varieties are yellow, green, pink
Hardness: 9
Optical effects: star effect
Most important deposits: Mozambique, Madagascar, Sri Lanka, Southeast Asia
For the formation of corundums a special geological environment is needed in which a surplus of aluminum is paired with a simultaneous lack of silicon, because otherwise, as is usually the case, no corundums develop; alumosilicates such as cyanite and andalusite form instead. Corundum is aluminum oxide. Its color is caused by trace elements.
The fact that blue corundum develops–sapphire, that is–is an anomaly owed to still other elements: iron and titanium. These must also be present in the same time and place. This explains the extreme rarity of sapphires in the earth's crust. The same can be said of different colored sapphires, which need certain combinations of elements, which have to be present in the correct amounts with aluminum and little silicon. For blue sapphire, iron and titanium are the correct combination.
Sapphires can sometimes be traced to a certain country of origin using microscopy. The analysis draws on the presence or absence, quantity, combination, and form of minerals, twin lamellae, rutile particle arrangement, and color distribution.
Likewise, healing fissures, which are the leftover traces of the fusion processes in the corundum, can provide information about the genesis, origin, and subsequent changes caused by humans on the basis of their appearance. Laboratories provide further details on the stones.
Deutsches Edelsteinhaus DEH GmbH
Chief Executive Officers: Alexander Streeb, Oliver Kleimaier
Commercial Register Number: HRB 737047
