Malachite

Object/Artifact

-

Crater Rock Museum

Name/Title

Malachite

Entry/Object ID

2014.1. 23

Description

Chemical Composition: Al(OH)3 Crystal System: Hexagonal System Description: Common Name: Malachite Chemistry: Cu2(CO3)(OH)2, Group: Carbonates Location: Congo, Africa Description: Small specimen with light and dark green orbs of banding. Physical Charateristics: •Color is banded light and dark green or (if crystalline), just dark green. •Luster is dull in massive forms and silky as crystals. •Transparency is opaque in massive form and translucent in crystalline forms. •Crystal System is monoclinic; 2/m. •Crystal Habitsin its massive forms are botryoidal, stalactitic or globular. Crystals are acicular or fibrous and form in tufts and encrustations. Frequently found as pseudomorphs of azurite. •Cleavage is good in one direction but rarely seen. •Fracture is conchoidal to splintery. •Hardness is 3.5-4. •Specific Gravity is 3.9+ (slightly heavy). •Streak is green. •Other Characteristics: Weakly effervesces in acid. •Associated Minerals include limonite, chalcopyrite, bornite, native copper, calcite, cuprite, azurite, chrysocolla and many rare copper minerals such as kolwezite, shattuckite, antlerite, brochantite, graemite, aurichalcite, sphaerocobaltite, atacamite, chalcophyllite, conichalcite, rosasite, chalcosiderite, clinoclase, cornetite, duftite, libethenite, liroconite, mixite and mottramite among others. •Notable Occurrences include many classic mineral localities such as Shaba, Congo; Tsumeb, Nambia; Ural mountains, Russia; Mexico; several sites in Australia; England and several localities in the Southwestern United States especially in Arizona, USA. •Best Field Indicators are color banding, softness, associations and reaction to acid. - See more at: http://www.galleries.com/malachite#sthash.NIDDm3iN.dpuf Hardness: 7 Quartz Rock Type: Sedimentary

Collection

RAGM Mineral Collection

Acquisition

Accession

2014.1

Source or Donor

Crater Rock Museum (unknown donors)

Acquisition Method

Gift

Dimensions

Height

2-1/4 in

Width

7/8 in

Length

1-3/8 in

Location

Location

Shelf

3rd shelf

Cabinet

Case# 20

Wall

West

Building

Freida Smith Hall

Category

Permanent