Corundum is a crystalline form of aluminium oxide (Al2O3) typically containing traces of iron, titanium, vanadium, and chromium. [3][4] It is a rock -forming mineral. It is a naturally …

Corund (Hungarian: Korond, Hungarian pronunciation: ) is a commune in Harghita County, Romania. It lies in the Székely Land , an ethno-cultural region in eastern Transylvania , in the …

2024年7月1日 · Corundum is a mineral that is primarily composed of aluminum oxide (Al2O3) and is one of the naturally occurring crystalline forms of aluminum oxide. It is a very hard mineral …

Corundum is a rock-forming mineral that is found in igneous, metamorphic, and sedimentary rocks. It is an aluminum oxide with a chemical composition of Al 2 O 3 and a member of the …

Corund sau, în maghiară, Korond, este cea mai mare și renumită localitate din Ținutul Sării. Nu poți separa numele Corund de ceramica populară, este centrul olăritului din Transilvania. …

2025年1月24日 · corundum, naturally occurring aluminum oxide mineral (Al 2 O 3) that is, after diamond, the hardest known natural substance. Its finer varieties are the gemstones sapphire …

Corundum is an aluminum oxide mineral of the oxides and hydroxides group, with structural formula Al2O3. The structure consists essentially of a dense arrangement of oxygen ions in …

Corundum is a very hard, tough, and stable mineral. For all practical purposes, it is the hardest mineral after Diamond, making it the second hardest mineral. It is also unaffected by acid s …

Corundum is a crystalline form of aluminum oxide (Al2O3) with traces of iron, titanium and chromium. It is a rock-forming mineral. It is one of the naturally transparent materials, but can …

Corund sau Korond, cum i se mai spune în limba maghiară, este un sat din județul Harghita cunoscut ca un important centru de ceramică, atât în Romania cât și în Europa. Este un sat cu …