Rhodochrosite

Object/Artifact

-

Crater Rock Museum

Name/Title

Rhodochrosite

Entry/Object ID

2009.62.319

Description

Chemical Composition: MnCO3 Crystal System: Hexagonal System Description: Common Name: Rhodochrosite Chemistry: MnCO3, Manganese Carbonate Class: Carbonates Location: Capillitas Mine, Andalgala, Catamarca, Argentina Description: Thick rounded slab with polished face. Beige to dull pink with irregular patterns somewhat linear. However, the sides have distinct banding, with some colors. PHYSICAL CHARACTERISTICS: Color is red to pink, sometimes almost white, yellow and brown. Luster is vitreous to resinous. Transparency: Crystals are transparent to translucent. Crystal System is trigonal; bar 3 2/m. Crystal Habits include the rhombohedrons and scalahedrons with rounded or curved faces that can obscure the crystal shape. Some crystals can be flattened to a bladed habit and these are sometimes aggregated into rosettes or minute crystals into spherules. Also botryoidal, globular, stalactitic, layered, nodular, vein-filling and granular. Twinning is somewhat common forming penetration twins and contact twins similar to calcite's twins. Cleavage is perfect in three directions forming rhombohedrons. Fracture is uneven. Hardness is 3.5 - 4. Specific Gravity is approximately 3.5 (above average) Streak is white. Other Characteristics: Pink and white banding in massive forms, non-fluorescence and specimens effervesce easily with dilute acids. Associated Minerals include calcite, ankerite, alabandite, rhodonite, bementite, spessartine, fluorite, manganite, quartz and many metal sulfides. Best Field Indicators are color, crystal habit, reaction to acid, non-fluorescence and perfect cleavage. Rock Type: Sedimentary Specific Gravity: 3.5 to 3.7

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Width

3-1/2 in

Depth

2 in

Length

7 in

Location

Location

Display Case

DS-8

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Curtis Gardner

Date

May 25, 2023

Notes

Added current location

Location

Container

Left

Drawer

Top Shelf

Shelf

Right

Cabinet

Case# 29

Building

Freida Smith Hall

Category

Permanent