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Chemical Formula | C | |||
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Composition | Carbon | |||
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Color | Silver-gray to black | |||
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Streak | Black | |||
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Hardness | 1 - 2 | |||
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Crystal Forms and Aggregates |
(Hexagonal) Crystals consist of thin hexagonal plates or distorted clusters of flaky plates on a matrix. Large thick hexagonal crystals are very rare. Most often occurs as veins; which may be very large, and in massive form. | |||
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Transparency | Opaque | |||
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Specific Gravity | 1.9 - 2.3 | |||
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Luster | Metallic | |||
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Cleavage | 1,1 - basal | |||
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Fracture | Conchoidal | |||
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Tenacity | Brittle; thin flakes slightly flexible | |||
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Other ID Marks | 1) Has a greasy feel 2) Smudges the hands when touched 3) Is a good conductor of electricity (although it does not conduct heat well) |
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Other Names |  Black Lead, Plumbago,
Grafito,
Pencil
Ore |
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Polymorphs | Diamond, Chaoite, Lonsdaleite | |||
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In Group | Native elements ; Nonmetallic elements | |||
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All About | Graphite is rather common, but fine crystals
are rare. Most Graphite mining areas produce enormous
quantities from a single or several large veins.
Graphite has the same chemical composition as Diamond, but their structure is entirely different which causes a tremendous contrast in their physical properties. Much care should be given to a Graphite specimen, especially thin crystals, which are fragile. It is very hard to wash crystals as they peel off and get ruined. Graphite will also smudge on its surface, and can get worn out if it is moved around too much. If handled, Graphite smudges the hands, and will smudge a paper or cardboard box if it is kept in one. |
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Uses | The "lead" in pencils is composed of graphite mixed with clay. Much of the commercially mined Graphite is used as pencil fillings. Its main function, however, is as a lubricant. It has many electrical uses, primarily because it is the only common nonmetal that is a good conductor of electricity. | |||
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Striking Features | Low weight, greasy feel, smudge, and low hardness | |||
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Popularity (1-4) | 1 | |||
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Prevalence (1-3) | 1 | |||
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Demand (1-3) | 1 | |||
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Distinguishing Similar Minerals |
There are quite a number of minerals similar in appearance to Graphite, but Graphite's intrinsic properties easily distinguish it. Molybdenite, commonly confused with Graphite, is heavier and not smudgy. | |||
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Commonly Occurs With |
Calcite, Quartz, Muscovite, Biotite (Marble, Limestone) | |||
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Noteworthy Localities |
Fine crystals are rare, but some worldwide localities are Pargas, Finland; Mount Vesuvius, Italy; and Borrowdale, Cumbria, England; Mont Saint-Sauveur, Quebec, Canada. In the U.S., large commercial deposits exist in Ticonderoga, Essex Co., New York, and in Clay Co., Alabama. Graphite as small flakes and plates is common at the Franklin Marble Belt, specifically at Amity, Orange Co., NY, and at Franklin, Ogdensburg, and Sparta, Sussex Co., New Jersey. Crystal masses and large plates have also come from Bear Mountain and West Mountain, Rockland County, New York. Flecks have also been found at the French Creek mine Chester Co., Pennsylvania; at Bisbee, Cochise Co., Arizona; and at Crestmore, Riverside Co., California. | |||
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Picture Icon Links |
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Picture Links | 1. Massive Graphite vein |
