What this coin looks like (obverse, reverse, mint mark location, special features, etc.): There were two major varieties of the 1905-O silver Barber Dime. The Micro "O" variety is the rarer and more valuable dime in which the "O" mint mark on the reverse of the coin was much smaller in size than normal. Depicted below is an example image comparing the difference between the 1905 Micro "O" vs the normal Big "O" Barber dimes.
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD