Sedimentary coppers as gemstone: a case study of copper mineralization in the alluvial sediments of the southern plain of Rafsanjan

The Pliocene-Quaternary sediments of the southern plain of Rafsanjan (west of Kerman province), have a variety of sedimentary copper minerals which can be used as gemstones and suitable for minerals/rocks colledctioners. The most important copper identified minerals include malachite, azurite, atacamite and paratacamite. Copper mineralization in this sequence is observed in three forms: cement (in conglomerates), nodules (in sandstones and tuffaceous mudstones), and alternating parallel to cross-laminations with calcite (travertines). The first two groups have only a decorative value, but the third group has the potential for jewelry making and is therefore presented as a gemstone. The leaching of copper from porphyry copper deposits in the upstream area (related to the Dehj-Sardouyeh belt) followed by the enrichment and deposition of copper in the young deposits downstream is considered the most probable model for the copper mineralization in the studied deposits. These deposits are called as exotic copper deposits.