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.
Rain Shadow *A dry area on one side of a mountain range or mountain *Caused by rising clouds that release their rain on one side of the mountain, called relief rain *Examples include the Gobi Desert and the east side of the Rocky Mountains