Dolomite

Object/Artifact

-

Crater Rock Museum

Name/Title

Dolomite

Entry/Object ID

78.63.212

Description

Chemical Composition: Carbonates Crystal System: Hexagonal System Description: Common Name: Dolomite Group Name: Dolomite Group Location: Missouri Chemistry: CaMg(CO3)2 Description: Delmar described this specimen as a calcite cluster from Mexico,( new information has determined that specimen is from Missouri). Colors: a medium fine calcite crystalline base(white) with some grey crystrals and pink stains with a large surrface of bladed large calcite crystals (off-white). PHYSICAL CHARACTERISTICS: • Color is often pink or pinkish and can be colorless, white, yellow, gray or even brown or black when iron is present in the crystal. • Luster is pearly to vitreous to dull. • Transparency crystals are transparent to translucent. • Crystal System is trigonal; bar 3 • Crystal Habits include saddle shaped rhombohedral twins and simple rhombs some with slightly curved faces, also prismatic, massive, granular and rock forming. Never found in scalenohedrons. • Cleavage is perfect in three directions forming rhombohedrons. • Fracture is conchoidal. • Hardness is 3.5-4 • Specific Gravity is 2.86 (average) • Streak is white. • Other Characteristics: Unlike calcite, effervesces weakly with warm acid or when first powdered with cold HCl. • Associated Minerals: include calcite, sulfide ore minerals, fluorite, barite, quartz and occasionally with gold. • Notable Occurrences include many localities throughout the world, but well known from sites in Midwestern quarries of the USA; Ontario, Canada; Switzerland; Pamplona, Spain and in Mexico. • Best Field Indicators are typical pink color, crystal habit, hardness, slow reaction to acid, density and luster. Fracture: Conchoidal Hardness: 3 Calcite Luster: Vitreous Rock Type: Sedimentary Specific Gravity: 2.7 Streak: White

Collection

:Delmar Smith Mineral Collection

Acquisition

Accession

78.63.213

Dimensions

Height

2-1/2 in

Width

6-3/4 in

Depth

3 in

Length

5-3/4 in

Dimension Notes

Dimension taken at widest points

Location

Location

Shelf

CS-D-7

Room

Curation Storage

Building

Crater Rock Museum

Category

Storage

Moved By

Curator

Date

February 21, 2024