Knowra Sapphire Sapphire Sapphire is gem-quality corundum, the crystalline form of aluminum oxide. Trace elements create its colors, while hardness and optical transparency make it valuable in jewelry and technology.
Corundum : Corundum is crystalline aluminum oxide, occurring naturally as a mineral and in gem varieties including sapphire and ruby. Sapphire is the gem variety of corundum, distinguished mainly by color.
Color center : A color center is a defect or impurity in a crystal that absorbs selected wavelengths of light. Impurities and defects selectively absorb light, producing sapphire’s visible hues.
Gemstone : A gemstone is a mineral or other natural material valued for beauty, rarity, and use in adornment. Sapphire’s color, transparency, and durability make it a widely used gemstone.
Ruby : Ruby is the red gem variety of corundum, colored chiefly by chromium. Ruby and sapphire are color-defined gem varieties of the same mineral.
Aluminum oxide : Aluminum oxide is a chemical compound of aluminum and oxygen, with formula Al₂O₃. It is the chemical substance forming sapphire’s crystal lattice.
Iron–titanium charge transfer : Iron–titanium charge transfer is an electronic transition between neighboring iron and titanium ions that absorbs visible light. This absorption is the principal cause of blue coloration in many sapphires.
Watch crystal : A watch crystal is a transparent cover protecting a watch dial or display. Synthetic sapphire is used for scratch-resistant watch covers.
Padparadscha sapphire : Padparadscha sapphire is a rare pink-orange variety of corundum associated with Sri Lanka. Its distinctive color forms a prized, narrowly defined sapphire category.
Crystal structure : A crystal structure is the ordered, repeating arrangement of atoms in a crystalline solid. Corundum’s specific atomic arrangement gives sapphire its characteristic hardness and optical behavior.
Chromium : Chromium is a chemical element whose ions can color minerals and glass. Chromium produces the red color of ruby, the red variety of corundum.
Show all 22