PHYSICAL PROPERTIES of CORUNDUM. ... Corundum Color: Ruby: pinkish red to red. Sapphire (all other colors): blue, pink, green, yellow, violet, purple, orange, brown, white, gray, black and colorless.

What colors can corundum be?

Corundum comes in all colours of the rainbow but is most commonly found as opaque crystals with dull colours. Red corundum is called ruby, blue corundum is called sapphire, and all other colours are called fancy sapphires.

What Colour is pure corundum?

Corundum in its pure state is colourless, but the presence of small amounts of impurities can impart a broad range of hues to the mineral. Ruby owes its red colour to chromium, sapphire its blue shades to the presence of iron and titanium; most corundum contains nearly 1 percent iron oxide.