Fluorite with Quartz

Object/Artifact

-

Crater Rock Museum

Fluorite / Quartz

Fluorite / Quartz

Name/Title

Fluorite with Quartz

Entry/Object ID

2009.62.122

Description

Chemical Composition: Calcium Fluoride Crystal System: Cubic or Isometric S Description: Common Name: Fluorite with Quartz Chemistry: CaF2, Calcium Fluoride / SiO2 , Silicon dioxide Class: Halides / Silicates Location: Xie Fang, Jiangxi Province, China Description: The fluorite crystal is translucent pale green with a multi-faceted cubic structure with a druzy white quartz crystal protruding from one end of it. 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. PHYSICAL CHARACTERISTICS OF QUARTZ: Color is as variable as the spectrum, but clear quartz is by far the most common color followed by white or cloudy (milky quartz). Purple (Amethyst), pink (Rose Quartz), gray or brown to black (Smoky Quartz) are also common. Cryptocrystalline varieties can be multicolored. Luster is glassy to vitreous as crystals, while cryptocrystalline forms are usually waxy to dull but can be vitreous. Transparency: Crystals are transparent to translucent, cryptocrystalline forms can be translucent or opaque. Crystal System is trigonal; 3 2. Crystal Habits are again widely variable but the most common habit is hexagonal prisms terminated with a six sided pyramid (actually two rhombohedrons). Three of the six sides of the pyramid may dominate causing the pyramid to be or look three sided. Left and right handed crystals are possible and identifiable only if minor trigonal pyramidal faces are present. Druse forms (crystal lined rock with just the pyramids showing) are also common. Massive forms can be just about any type but common forms include botryoidal, globular, stalactitic, crusts of agate such as lining the interior of a geode and many many more. Cleavage is very weak in three directions (rhombohedral). Fracture is conchoidal. Hardness is 7, less in cryptocrystalline forms. Specific Gravity is 2.65 or less if cryptocrystalline. (average) Streak is white. Other Characteristics: Striations on prism faces run perpendicular to C axis, piezoelectric (see tourmaline) and index of refraction is 1.55. Associated Minerals are numerous and varied but here are some of the more classic associations of quartz (although any list of associated minerals of quartz is only a partial list): amazonite a variety of microcline, tourmalines especially elbaite, wolframite, pyrite, rutile, zeolites, fluorite, calcite, gold, muscovite, topaz, beryl, hematite and spodumene. Best Field Indicators are first the fact that it is very common (always assume transparent clear crystals may be quartz), crystal habit, hardness, striations, good conchoidal fracture and lack of good cleavage Fracture: irregular and brittl Hardness: 4 Flourite Luster: Vitreous Occurrence: Fluorite may occur as a vein deposit, especially with metallic minerals, where it often forms a part of the gangue (the worthless "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: 3.1 Streak: white

Collection

RAGM Mineral Collection

Acquisition

Accession

2009.62

Source or Donor

Museum Collection of Minerals

Acquisition Method

Donation

Dimensions

Width

2 in

Depth

4 in

Length

6-1/4 in

Weight

3.34 oz

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

Drawer

3rd from the left

Shelf

bottom left middle, bottom left middle

Wall

West wall

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent

Moved By

Jacob Rier

Date

September 26, 2009

Location

Container

Center

Drawer

Bottom / Center

Shelf

Left

Cabinet

Case #39

Wall

West wall

Room

Delmar Smith Hall

Building

Crater Rock Museum

Category

Permanent