Ads
related to: magnesium aluminium spinel jewelry
Search results
Results From The WOW.Com Content Network
Polyhedral representation of spinel MgAl 2 O 4. Spinel (/ s p ɪ ˈ n ɛ l, ˈ s p ɪ n əl / [7]) is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula MgAl 2 O 4 in the cubic crystal system. Its name comes from the Latin word spinella, a diminutive form of spine, in reference to its pointed crystals. [5]
All red gemstones used to be referred to as rubies or "balas rubies". It was not until 1783 that spinels were chemically differentiated from rubies. [5] They both contain aluminium and oxygen, and both derive their colour from chromium(III), but the spinel crystal also contains magnesium, which rubies lack.
The heterogeneity of spinel group members varies based on composition with ferrous and magnesium based members varying greatly as in solid solution, which requires similarly sized cations. However, ferric and aluminium based spinels are almost entirely homogeneous due to their large size difference.
The first crystalline artificial diamond simulants were synthetic white sapphire (Al 2 O 3, pure corundum) and spinel (MgO·Al 2 O 3, pure magnesium aluminium oxide). Both have been synthesized in large quantities since the first decade of the 20th century via the Verneuil or flame-fusion process, although spinel was not in wide use until the ...
It and a smaller 270-carat (54 g) spinel were captured and taken to Iran by Nader Shah following his 18th-century invasion of India.. The Samarian spinel has a hole in it. According to a diary entry of the court physician to Naser al-Din Shah Qajar, the shah told the physician that the stone once adorned the neck of the biblical golden calf, which the Israelites are said to have made while ...
Corundum is a crystalline form of aluminium oxide (Al 2 O 3) typically containing traces of iron, titanium, vanadium, and chromium. It is a rock -forming mineral . It is a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure.