Ruby / Corundum:
Velvet is a type of woven tufted fabric in which the cut threads are evenly distributed, with a short dense pile, giving it a distinctive feel. Velvet can be made from either synthetic or natural fibers.
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.