Ruby / Corundum:
Precious stones are the most beautiful and valuable of all the gemstones. Their colors are vibrant, translucent and brilliant. These natural crystals are also durable, but at the same time rare, and they can be used to create both jewelry and accessories.
Ruby / Corundum is a crystalline form of aluminum oxide (Al2O3) typically containing traces of iron, titanium, vanadium and chromium. It is one of the naturally transparent materials, but can have different colors when impurities are present. Transparent specimens are used as gems, ruby if red and padparadscha if pink-orange. All other colors are called sapphire, e.g., "green sapphire" for a green specimen. Because of corundum's hardness (pure corundum is defined to have 9.0 Mohs), it can scratch almost every other mineral.