Fluorite

Object/Artifact

-

Crater Rock Museum

Name/Title

Fluorite

Entry/Object ID

2009.62.65

Description

Chemical Composition: CaF2 Crystal System: Orthorhombic System Description: Common Name: Fluorite Chemistry: CaF2, Calcium Fluoride Group: Halides Location: Harden County, Illinois Description: Large mass of small cubic crystals light translucent green in color, on a blackish, gray matrix. THE PHYSICAL CHARACTERISTICS OF FLUORITE: Color is extremely variable and many times can be an intense purple, blue, green or yellow; also colorless, reddish orange, pink, white and brown. A single crystal can be multi-colored. Luster is vitreous. Transparency: Crystals are transparent to translucent. Crystal System: Isometric; 4/m bar 3 2/m Crystal Habits include the typical cube and to a lesser extent, the octahedron as well as combinations of these two and other rarer isometric habits. Always with equant crystals; less common are crusts and botryoidal forms. Twinning also produces penetration twins that look like two cubes grown together. Cleavage is perfect in 4 directions forming octahedrons. Fracture is irregular and brittle. Hardness is 4 Specific Gravity is 3.1+ (average) Streak is white. Other Characteristics: Often fluorescent blue or more rarely green, white, red or violet and may be thermoluminescent, phosphorescent and triboluminescent. Associated Minerals are many and include calcite, quartz, willemite, barite, witherite, apatite, chalcopyrite, galena, sphalerite, pyrite and other sulfides. Best Field Indicators are crystal habit, color zoning, hardness (harder than calcite, but softer than quartz or apatite), fluorescence and especially the octahedral cleavage. Fracture: conchoidal Hardness: 3 Calcite Luster: Vitreous Occurrence: Fluorite may occur as a vein deposit, especially with metallic minerals, where it often forms a part of the gangue (the surrounding "host-rock" in which valuable minerals occur) and may be associated with galena, sphalerite, barite, quartz, and calcite. It is a common mineral in deposits of hydrothermal origin and has been noted as a primary mineral in granites and other igneous rocks and as a common minor constituent of dolostone and limestone. Rock Type: Sedimentary Specific Gravity: 2.2 Streak: white Texture: Crystalline Variety: Fluorite is a widely occurring mineral which is found in large deposits in many areas. It also comes in a rainbow of colors and is refer to as the most colorful mineral in the world.

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Height

2 in

Width

2-3/4 in

Length

6-1/2 in

Weight

21.58 oz

Dimension Notes

Dimension taken at widest points

Location

Location

Display Case

DS-8

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Curtis Gardner

Date

May 24, 2023

Notes

Added current location

Location

Container

Center

Drawer

3rd Shelf

Shelf

Center, Center

Wall

South wall

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Steve Miller

Date

January 14, 2010

Location

Container

Right

Cabinet

Case #39

Wall

West

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Container

Center

Drawer

3rd Shelf

Shelf

Center, Center