Rock butter
Encyclopedia
Rock butter is a soft mineral
substance found oozing from alum
slates.
It consists of native alum mixed with clay
and oxide of iron, usually in soft masses of a yellowish white colour, occurring in cavities and fissures in argillaceous slate.
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
substance found oozing from alum
Alum
Alum is both a specific chemical compound and a class of chemical compounds. The specific compound is the hydrated potassium aluminium sulfate with the formula KAl2.12H2O. The wider class of compounds known as alums have the related empirical formula, AB2.12H2O.-Chemical properties:Alums are...
slates.
It consists of native alum mixed with clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...
and oxide of iron, usually in soft masses of a yellowish white colour, occurring in cavities and fissures in argillaceous slate.