| Description |
A rock may be defined as one, or an aggregate of rock forming materials, constituting an integral part of the Earth's crust, and having sufficient characteristic to establish its identity. The minerals forming rocks are interlocked and held together by inter molecular attraction, or cemented together by some extraneous material, or in rare cases they are cemented together by material produced from the minerals themselves by a process of attrition or friction. A rock forming mineral is defined to be of definite chemical composition and crystalographic form, that is, it contains fixed amounts of tow or more chemical elements, and when solidified or crystalized from a solution it assumes a form bounded by certain planes which are constant for each mineral. |
