Name/Title
GraphiteEntry/Object ID
LN2012.1.21Description
Chemical Composition: C
Crystal System: Hexagonal System
Description: Common Name: 'Lump' Graphite (also called vein graphite)
Group Name: Element (C),
Location: unknown
Chemistry: Carbon (C)
Description: Silver-gray, irregular nodules of graphite. Two dissimilar pieces.
PHYSICAL CHARACTERISTICS:
The mineral graphite is an allotrope of carbon. Unlike diamond (another carbon allotrope), graphite is an electrical conductor, a semimetal. It is, consequently, useful in such applications as arc lamp electrodes. Graphite is the most stable form of carbon under standard conditions. Therefore, it is used in thermochemistry as the standard state for defining the heat of formation of carbon compounds. Graphite may be considered the highest grade of coal, just above anthracite and alternatively called meta-anthracite, although it is not normally used as fuel because it is difficult to ignite.
Color: Iron-black to steel-gray; deep blue in transmitted light
Crystal habit: Tabular, six-sided foliated masses, granular to compacted masses
Crystal system: Hexagonal
Twinning: Present
Cleavage: Basal – perfect on {0001}
Fracture: Flaky, otherwise rough when not on cleavage
Tenacity: Flexible non-elastic, sectile
Mohs scale hardness: 1–2
Luster: Metallic, earthy
Streak: Black
Fracture: flaky, otherwise rou
Hardness: 2 Gypsum
Luster: Metallic
Occurrence: Graphite occurs in metamorphic rocks as a result of the reduction of sedimentary carbon compounds during metamorphism. It also occurs in igneous rocks and in meteorites. Minerals associated with graphite include quartz, calcite, micas and tourmaline. In meteorites it occurs with troilite and silicate minerals.
Rock Type: Metamorphic
Specific Gravity: 1.9 - 2.3
Streak: black
Variety: There are three principal types of natural graphite, each occurring in different types of ore deposit:
1.Crystalline flake graphite (or flake graphite for short) occurs as isolated, flat, plate-like particles with hexagonal edges if unbroken and when broken the edges can be irregular or angular;
2.Amorphous graphite occurs as fine particles and is the result of thermal metamorphism of coal, the last stage of coalification, and is sometimes called meta-anthracite. Very fine flake graphite is sometimes called amorphous in the trade;
3.Lump graphite (also called vein graphite) occurs in fissure veins or fractures and appears as massive platy intergrowths of fibrous or acicular crystalline aggregates, and is probably hydrothermal in origin.Collection
Carol Swisher Mineral-Uses CollectionDimensions
Width
1 inDepth
3/8 inLength
1-3/16 inDimension Notes
Dimension taken at widest points.
Two pieces:
1.2 x 1.0 x 0.4 inches
1.5 x 0.6 x 0.6 inchesLocation
Location
* Untyped Location
Needs Updated Location - 2022Category
Permanent
