Carbon-free What caffeine-free is to Coke, carbon-free is to the surface of coins. Often, carbon spots will form on the surface of silver, nickel, or copper coins, damaging them to a certain extent and lowering the value.
Carbon Spots:
Not really carbon in the chemical sense but a term to describe dark spots on the coin's surface. Generally the result of mishandling.
Choice:
A term to describe a particularly nice example (See Gem and Proof Like).
Coin: ...
carbon spot A spot seen mainly on copper and gold coins, though also occasionally found on U.S. nickel coins (which are 75 percent copper) and silver coins (which are 10 percent copper).
carbon spot: a small spot of corrosion or oxidation on a coin caused by a spot of moisture. When you talk around coins - Say it, don't spray it!
Carson City: official U.S. Mint in Carson City, Nevada that issued coins from 1870 to 1893.
Carbon spot - A dark discoloration on the surface of a coin, possibly caused by a planchet imperfection prior to striking, or it may be caused by improper storage of the coin.
Carbon Spots - These are small black spots of carbon that appear on a coin. They can not be removed and can grow over time.
Cartwheel Effect - The effect a highly lusterous coin has when rotated in a circular motion ...
carbon spot: a brown or black spot on a coin, caused by impurities or oxidation
cartwheel: a visual effect where the coin's luster appears to spin in a radiating fashion. Considered desirable.
Carbon Spot
A term used to describe the colour of dark spots found on the surface of a coin. The spots do not normally comprise the chemical 'carbon' and are more commonly found on bronze coins.
Center Thread ...
carbon spots - Spots seen primarily on gold and copper coins. Carbon spots are dark brown to black spots of oxidation. Carbon spots can decrease overall quality and value of a coin.
CARBON SPOT
A dark discolouration upon the surface of a coin thought to be composed of organic material such as wood, sawdust, coal particles, etc., which was residing on the planchet prior to annealing.
Carbon spot
A dark discoloration on the surface of a coin. It is possible that this discoloration is caused by a planchet imperfection prior to striking, or it may be caused by improper storage of the coin.
Carbon Spots - Small spots of corrosion, usually seen on copper coins.
Carbon Spot
A black discoloration on a coin which was on a PLANCHET prior to the ANNEALING process. The discoloration may have been caused by burnt wood or sawdust, charcoal particles or sulfides.
Carbon Spot - Brown or black spots usually found on copper and gold coins. The spotting is caused by oxidation and, if severe, prevents a coin from being graded.
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Nickel carbonyl, [Ni(CO)4], is an extremely toxic gas. The toxicity of metal carbonyls is a function of both the toxicity of the metal as well as the compound's ability to give off highly toxic carbon monoxide gas, and this one is no exception.
Copper(II) carbonate is green from which arises the unique appearance of copper-clad roofs or domes on some buildings. Copper(II) sulfate forms a blue crystalline pentahydrate which is perhaps the most familiar copper compound in the laboratory.
wikiHow is a carbon neutral website
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carbon streaking: Black streaks across a copper coin
cartwheel luster: The natural reflectivity of a brilliant finish coin in which luster will reflect down the diameter of a coin ...
Contaminants/Carbon Flaking Dies were first annealed by heating. They were then packed in carbon for the gradual cooling. Sometimes the carbon was not completely washed off prior to the dies being used.
Low-grade carbon steel formed the base of these coins, to which a zinc coating .005 inch thick was deposited on each side electrolytically as a rust preventative.
Polypropylene is a neutral plastic containing only 2 elements Carbon and Hydrogen. Polypropylene doesn't use any dangerous chemicals in it's production. Polypropylene sheet is manufactured from propylene monomer which is a relatively safe gas.
All the coins were uncirculated, but many showed carbon flecks from moisture in the atmosphere.
Some gold coins over time pick up subtle light brown or orange-brown streaks or spots, called copper spots or carbon spots (though carbon plays no role in their formation), which may have been caused by incompletely mixed copper in the alloy, ...
drawn from carbon 14 test was delivered in 1988: its conclusions was that the shroud is a work dating from the beginning of the 14th century. Many people
accepted this decision as final.
A combination of iron, carbon and another element, usually nickel, to prevent rusting.
Striations
Thin, light raised lines on the surface of a coin, caused by excessive polishing of the die.
Striking ...
The first, the Flowing Hair motif minted in 1794 and 1795, is a stylistic carbon copy of the contemporary half dime and half dollar.
As the strip grew ever longer during this process, small inclusions of carbon or foreign material, or imperfectly mixed copper added to the ingot as an alloy, or air bubbles, became distended or lengthened.
There are several types of natural patinations but the vast majority will be either of copper oxide (mostly brown or black) or copper carbonate (usually green and sometimes blue), ...
Copper is a chemically active metal and, depending on the storage environment, can suffer from carbon spots and corrosion marks. These imperfections must be considered when grading.
Stainless Steel
A combination of iron, carbon and another element, usually nickel, to prevent rusting.
Striations
Thin, light raised lines on the surface of a coin, caused by excessive polishing of the die.
however it is rarely found on coins made for general circulation and is less common on coins minted prior to the mid-1960's. Attractive early cameo coins often sell for substantial premiums over non-cameo's of the same date and mint mark. carbon ...
Hub - a mirror image copy of a die in relief which was used to make "carbon copy" dies ...
I have read of other similar markings, but haven't seen them in my limited experience. Possibly, only the highest grade coins will show these markings. Many of the higher grade coins I've seen have been marred with unattractive carbon spots.
I found, when excavations were being made on the acropolis of Athens among the debris of the conflagration of Xerxes, fragments of their bronze draperies with carbonized wood still in them, ...
 See also: Coin, Copper, Silver, Gold, Collector
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