Sapphire
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Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, bo
Main sapphire-producing countries
Teardrop-shaped blue sapphire
The 193.39 carat Star of Lanka star sapphire
Sapphire ring made c. 1940
Ruby
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Ruby is a pinkish-red to blood-red-colored gemstone, a variety of the mineral corundum, consisting of aluminium oxide. Ruby is one of the most popular traditional jewelry gems and is very durable. Oth
Sapphire
…and can be in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors. Red corundum stones also occur, but are called rubies rather than sapphires. Pink-colored corundum may be classified either as ruby or sapphire depending on the locale. Commonly, natural sapphires are cut…
A ruby crystal from Dodoma Region, Tanzania
The main ruby-producing countries
Crystal structure of ruby showing the substitution of Al3+ ions (blue) with Cr3+ (red). The substitution density of Cr3+ ions in this model is approximately 2%, approximating the maximum doping normally encountered.
Ruby (Corundum) - Hunza Valley, div. Gilgit, Northern Areas, Pakistan.