allophane

[In Ger. allophan; Gr. ἄλλος ( allos ) = another, and φαίνω ( phainō ) = to make to appear. The reference is to its change of appearance under the blow-pipe.] A mineral cla ed by Dana as the first of his Sub-silicates. It occurs amorphous, in incrustations, stalactitic, or nearly pulverulent. It is pale sky-blue, green, brown, yellow, or colourle . Its hardne is 3; sp. gr. 1.851.89. It is very brittle. It consists of silica, 19.8 to 24-11 parts; alumina, 32-20 to 41 parts; water, 3574 to 44-20, with a little lime. ǎl-lo-phăn'-ic, a [Gr. ἄλλος ( allos )= another, and φαίνω ( phaino ) = to cause to appear.] Pertaining to anything which changes its appearance, or of which the aspect is altered. allophanic acid, s. Chem.: C2N2H403 A mon ureide of carbonic acid obtained by pa ing the vapour of cyanic acid into absolute alcohol.