Strontianite

Object/Artifact

-

Crater Rock Museum

Name/Title

Strontianite

Entry/Object ID

78.63.230

Description

Chemical Composition: SrCO3, Crystal System: Orthorhombic System Description: Common Name: Strontianite Chemistry: SrCO3, Strontium Carbonate Group Name: Aragonites Location: Hardin County, Illinois Description: Delmar described this specimen as a piece of sediment material with top layer of aragonite. Color: Base is a sedimentary rock in stripes of white, greys and tan with a thick top layer of white aragonite crystals. PHYSICAL CHARACTERISTICS: •Color is white, colorless, gray, yellowish or greenish. •Luster is vitreous to greasy. •Transparency crystals are transparent to translucent. •Crystal System is orthorhombic; 2/m 2/m 2/m •Crystal Habits include compact, granular, concretionary and massive forms. Crystals are uncommon and are usually pointed and nearly acicular in radiating clusters or tufts. Also forms a psuedo-hexagonal trilling twin is similar to, but is far rarer than aragonite's famous twin. •Hardness is 3.5-4 •Specific Gravity is 3.7+ (above average for transparent minerals) •Cleavage is notable in one direction and poor in another. •Fracture is subconchoidal to uneven. •Streak is white. •Other Characteristics: effervesces in only warm HCl solutions or when powdered in cold HCl. •Associated Minerals include fluorite, celestite, galena, calcite and aragonite. •Notable Occurrences include Strontian, Scotland; San Bernito Co, California and Cave-in-rock, Illinois, USA; Austria and Germany. •Best Field Indicators are crystal habits, reaction to acid and density. Fracture: sub-conchoidal Hardness: 3 Calcite Luster: Vitreous Rock Type: Sedimentary Specific Gravity: 3.7+ Streak: white

Collection

Suomynona Collection

Acquisition

Accession

78.63

Source or Donor

Delmar Smith Crystal Collection

Acquisition Method

Donation

Dimensions

Width

2-1/4 in

Depth

1 in

Length

4-3/8 in

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

FS-4

Room

Frieda Smith Hall

Building

Crater Rock Museum

Category

Exhibit

Moved By

Ian C.

Date

January 29, 2025

Notes

Major mineral groups installation

Location

Display Case

FS-4-B

Room

Frieda Smith Hall

Building

Crater Rock Museum

Date

January 3, 2024