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Friday, October 29, 2010

Proof vs UNC coins

Many people have been asking me of late that what is the difference between proof and UNC coins? So I decided to put up a small one on this topic, as I believe that very few people are clear with this concept.Technically speaking, proof and UNC are different qualities. UNC is, by definition, an uncirculated coin which has mint lustre and has lots of shine to it. In case of a 100-year old coin, even if it has some shine it is liable to be classified as UNC. By definition, proof is the highest quality, even higher than UNC. So how can some coin have higher quality than even UNC coin, which is in its original state as it was when it was manufactured. The answer lies in the manufacturing process. The "proof" word is used as it is in dustproof, fireproof etc. by definition, a proof coin has to be at least double struck, and the blanks for preparing the coins are very carefully selected with a selection ratio of less than 20%. After the striking, again the selection ratio is less than 20%. Every sort of precaution has to be taken to ensure the quality of output. Proof coins are also polished and are shinier and have much better finish as compared to UNC coins. There is a higher level of contrast between the raised part and the shallow part in the design of the coin. The raised part is given a matt finish, which is achieved by sand-blasting the die. ordinary UNC coins (which had been circulated but have some lustre or shine usually have some bag marks, which are small scratches made during the handling of the coin, and these can be seen by magnifying the coin. On the other hand, a coin can be called a proof coin only if there are no scratches to be seen on it even when we look at it through a low power microscope.

All that being said, I am not sure whether these quality parameters are followed by Indian mints during production of the coins. It IS a fact that the term proof is a highly misused term, people often do not know the meaning but say they have a proof coin. Even many government mints also misuse the term as the stringent production process is not adhered to. So its hard to say whether the proper process is followed in the Indian mints or not. If you take out a proof coin from its packing and touch the coin, your fingerprints will come on the coin. If there is any such mark on the coin, it cannot be called a proof coin even though it may have the different mint mark. The quality of the proof coin is supposed to be better than that of a UNC coin, definitely not lower. Though if the coin is more than 100 years old, even a coin which does not have shine is called proof because it was made as a proof strike, that would be fair enough. Lets say we are talking of a William mohur or a Victoria sovereign of which a proof strike was made, we wont be getting that quality, but still its fair enough to call it proof because firstly, very very few such coins were made. And secondly, no coin would be existing on this date with the original manufacturing condition totally intact. If these coins have that finish, that is good enough.

Now we have a look at proof and UNC coins minted on the same theme minted by the Mumbai mint and compare them to see the difference. The theme of these coins is the first war of independence.

First war of independence UNC coin
first war of independence uncNote the diamond mint mark below the date

First war of independence Proof coin
first war of independence proofNote the 'M' mint mark below the date. The 'M' here stands for Mumbai as this coin was minted in the Mumbai mint.

P.S. Kolkata coins have no mint mark, so they cannot be differentiated by the mint mark.

Also, it is noteworthy to see that the proof and UNC coin shown here have difference as the proof coin is having much higher contrast, the raised part is white as it is coated and also it is shinier than the UNC coin.

For investment purpose the proof coins are generally a better bet as the value of proof coin is always higher than a UNC coin. That said, I would suggest people to buy what pleases them, and also the budget is always an essential factor in deciding what to buy and what not to buy.


  1. I have 10 rupee king George note which was sea sunk in 1917 during war in campberwell ship its extremly rare to find. note can be not seen by naked eye if expose in sun light clearly we can see the water marks along with reserve bank of India ten rupee. Please give me more details and tell me current expected value?
    Best Regards
    K Sonkar

  2. so for collection which one is best UNC or Proof Coins....

  3. that is your decision to make. If you ask me I will say proof is better, but proof is also costlier so it puts more stress on your pocket.

  4. This comment has been removed by the author.

  5. i would like to buy some proof sets , where can i get them. i live near kolkata

  6. I want to buy proof n unc set ..where it vil get..i live in bellary karnataka

  7. How many commemorative sets of Proof / UNC are minted by RBI for sale to collectors