RESERVE BANK OF INDIA GOLDEN JUBILEE 50 PAISE: "FILLED DIE" ERROR

In the year 1985 Commemorative Cupro-Nickle 50 Paise coins were released from Bombay, Kolkata and Hyderabad Mint, in order to commemorate the golden jubilee of RBI (1935-1985). In case of Bombay minted coin recently I found this interesting error, which is commonly known as "Filled Die Error". This error occurs when the lubricant (generally, Grease) applied to the machinery parts of the die gets clogged into the actual die which is minting coin. In the above displayed pair of coins, Lion head on the left side is normal one and the one on the right side is the Greased head tip, where the grease gets clogged into the tip of the head (ear part) design as a result this part becomes filled with grease (hence called as Filled Die Error) and we will not get its impression on coin, leading to such errors.