Rhodochrosite

Object/Artifact

-

Crater Rock Museum

Name/Title

Rhodochrosite

Entry/Object ID

2009.62.93

Description

Chemical Composition: MnCO3 Crystal System: Tetragonal System Description: Common Name: Rhodochrosite Chemistry: MnCO3, Manganese Carbonate Group: Carbonates Location: ? Description: Worm-like crystals with a druzy covering, dull pink in color on a grainy pink and black matrix. 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. Fracture: conchoidal Hardness: 3 Calcite Luster: Vitreous Occurrence: Rhodochrosite occurs as a hydrothermal vein mineral along with other manganese minerals in low temperature ore deposits. Rock Type: Sedimentary Specific Gravity: 3.5 Streak: white Variety: Rhodochrosite (whose name means rose-colored) is a very attractive mineral with an absolutely one-of-a-kind, beautiful color. Although it can be an ore of manganese, it is its ornamental and display specimen qualities that make it a very popular mineral. The color of a single crystal can just astound the observer with its vivid pink-rose color that seems to be transmitted out of the crystal as if lit from within. Individual crystals are found in well shaped rhombohedrons and more rarely scalahedrons

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Width

1-3/4 in

Depth

1 in

Length

2-1/2 in

Weight

0.25 oz

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

FS-11

Room

Frieda Smith Hall

Building

Crater Rock Museum

Category

Exhibit

Moved By

Ian C.

Date

January 29, 2025

Notes

Inventory/ location

Location

* Untyped Location

RD-8

Category

Permanent

Moved By

Curtis Gardner

Date

May 25, 2023

Notes

Added current location