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Chemical Formula | Hg | ||
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Composition | Mercury, occasionally associated with silver | ||
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Variable Formula | (Hg,Ag) | ||
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Color | Tin-white | ||
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Streak | --- | ||
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Hardness | --- | ||
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Crystal Forms and Aggregates |
(Amorphous) Mercury occures as small liquid blobs perched atop or in the crevices of mercury ores. Since Mercury is a liquid, it lacks a crystal structure and technically is not really a mineral but a mineraloid. However, most reputable mineral guides, including the acclaimed Dana's System of Mineralogy, categorize Mercury together with the "true" minerals. | ||
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Transparency | Opaque | ||
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Specific Gravity | 13.5 | ||
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Luster | Metallic | ||
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Cleavage | --- | ||
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Fracture | --- | ||
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Tenacity | --- | ||
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Other ID Marks | 1) Occurs in a liquid state 2) Very good conductor of electricity |
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Other Names |  Native Mercury,  Quicksilver,
Liquid
Silver, Hydrargyrum |
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In Group | Native elements ; Metallic elements | ||
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All About | Mercury is rare in a native state. Although it is a naturally occuring liquid substance, it is
never found in "pools". It only occurs as tiny
blobs on top of mercury ores such as Cinnabar. The tiny blobs are lodged
in small crevices or pores, or just stick to the
host mineral. The blobs do not roll around or fall
off, but stay attached in position unless tampered with. Mercury freezes at -38º F (-39º C), and when it solidifies, it crystallizes in the isometric system. (Under high pressure it crystallizes in the tetragonal system.) Mercury boils at a very low temperature, and disappears as fumes when heated. Because Mercury is a liquid, it is not possible for it to have a streak, hardness, cleavage, or crystals. |
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Uses | Native Mercury is only of use to the mineral
collector as a specimen of interest. The amount of
mercury mined with the ores
is too insufficient to mention Mercury as an ore, although its occurence is always with other mercury ores. Mercury as an element has many industrial uses, as it is the only metal that is a liquid at room temperature. It is used in many scientific and household devices, such as the mercury thermometer. When mercury combines with any of the true metals (excluding platinum and iron), the result is an amalgam. (There is a mineral known as "Amalgam", which is a mixture of silver and mercury (Ag,Hg), but the common term of amalgam denotes a mixture of mercury and any other metal.) Amalgams are used to extract precious metals from their ore. Ingested mercury and mercury mixtures are dangerous to health, and be lethal if a large amount is ingested. Hands should be washed when handling any minerals containing mercury. Some mercury mixtures are used as poison. Mercury vapor can be deadly if inhaled. |
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Striking Features | Liquid state and association with mercury ores | ||
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Complex Tests | When heated past the boiling point of 675° F (357° C), it will volatilize. | ||
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Popularity (1-4) | 1 | ||
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Prevalence (1-3) | 3 | ||
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Demand (1-3) | 2 | ||
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Distinguishing Similar Minerals |
The distinctive properties of Mercury and its environment can distinguish it from every mineral. | ||
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Commonly Occurs With |
Cinnabar, Calomel, Quartz, Dolomite | ||
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Noteworthy Localities |
The locality that yields the most and the
finest Native Mercury for collectors is Almadén, Ciudad
Real, Spain, where small blobs are found in the
host Cinnabar. Many small blobs have also come
from the mercury mines in Idrija, in former Yugoslavia (Slovenia) and in the Levigliani mine in Stazzema, Tuscany, Italy. In the U.S., Mercury occurs in several California mercury mines, specifically the Almaden and New Almaden mines in Santa Clara Co.; the Socrates Mine, Sonoma Co.,; and the New Idria District, San Benito Co. |
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Picture Icon Links |
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Picture Links | 1. Mercury blobs on Cinnabar |
