Corundum has two primary gem varieties: ruby and sapphire. Rubies are red due to the presence of chromium, and sapphires exhibit a range of colors depending on what transition metal is …

Ruby and sapphire gemstones are based on the simple chemical compound alumina, Al 2 O 3, also known as corundum. The color in ruby is attributed to the presence of chromium in …

It is commonly called alumina and may also be called aloxide, aloxite, or alundum in various forms and applications. It occurs naturally in its crystalline polymorphic phase α-Al 2 O 3 as the …

Alumina, or aluminium oxide (aluminum oxide), is better known in the mineral world as corundum. Because of its high melting point and resistance to chemicals it is NOT used as an ore of …

Mar 7, 2025 · Corundum, naturally occurring aluminum oxide mineral (Al2O3) that is, after diamond, the hardest known natural substance. Its finer varieties are the gemstones sapphire …

Jun 30, 2023 · Aluminum oxide, with the chemical formula Al2O3 A l 2 O 3, is an amphoteric oxide and is commonly referred to as alumina. Corundum (α-aluminum oxide), emery, sapphire, …

Alumina, also known as aluminium oxide, is a chemical compound with the formula Al₂O₃. It is a white or nearly colourless crystalline substance that occurs naturally in the mineral corundum, …

In the realm of advanced ceramics, alumina (Aluminum Oxide, Al2O3) and corundum, a crystalline form of alumina, stand out for their exceptional properties and versatility. These …

The following is a list of Aluminum gems and minerals listed in our database. Click the pictures to get full data, click the X to remove the gem from the list. Dumortierite: Dumortierite is a variety …

There are two main gemstones associated with aluminum oxide: ruby and sapphire. Learn about these and the other crystal formations in this article.