It is commonly called alumina, and may also be called aloxide, aloxite, or alundum depending on particular forms or applications. It commonly occurs in its crystalline polymorphic phase Î±-Al 2 O 3, in which it composes the mineral corundum, varieties of which form the precious gemstones ruby and sapphire.
rain cloud. (meteorology). Any cloud from which rain falls; a popular term having no technical denotation. 1  Facebook. 2  Twitter.
Stratus clouds can bring rain, snow, or fog. Science Words. Evaporate-when molecules warm up and change from a liquid into a gas. Water Vapor-when water from the Earth evaporates into the air, it becomes a gas and is called water vapor. Condense-when a gas cools down and turns back into a liquid.