A rough version of crystal is usually cut from a much larger piece of mined material that is too large or heavy to be used by a person. Rough chunks such as calcites are often acid-washed to subtly smooth out rough edges that may cause cuts or injury and to prevent further flaking or breakage.

A rough version of crystal is usually cut from a much larger piece of mined material that is too large or heavy to be used by a person. Rough chunks such as calcites are often acid-washed to subtly smooth out rough edges that may cause cuts or injury and to prevent further flaking or breakage.