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.
Snow falls from nimbostratus clouds. Nimbostratus clouds are grey, thick, low-level cpouds that cover the entire sky. These kinds of clouds are associated with prolonged weather, mainly rain or snow. Fun fact : The root word for nimbus, 'nimbo', is Latin for rain or precipitation and the root word for stratus, 'strato', is Latin for layer.