paratacamite

from The Century Dictionary.

• noun An oxychlorid of copper having the same percentage composition as atacamite, but losing its water at a higher temperature. It occurs in pseudorhombohedral crystals, and is found at Sierra Gorda, Chile.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mineralogy A rhombohedral form of basic copper chloride that is dimorphous with tacamite