Sheldon Rarity Scale
SRS = Sheldon Rarity Scale, developed by Dr. William H. Sheldon in his 1958 "Penny Whimsy"
| R-1 | Common | |
| R-2 | Not So Common | |
| R-3 | Scarce | |
| R-4 | Very Scarce | (76-200 known) |
| R-5 | Rare | (31-75 known) |
| R-6 | Very Rare | (13-30 known) |
| R-7 | Extremely Rare | (4-12 known) |
| R-8 | Unique or
Nearly Unique | (1-3 known) |
A plus sign (e.g. R-6+) indicates a higher degree of rarity
VAM Rarity Scale
VRS = VAM Rarity Scale, developed by Van Allen & Mallis in their "Comprehensive Catalog and Encyclopedia of Morgan and Peace Dollars" - a modification of the Sheldon Rarity Scale to account for the larger quantities of Silver Dollars
| R-1 | Common | (Tens of Millions) |
| R-2 | Not so Common | (Several Million) |
| R-3 | Scarce | (Hundreds of Thousands) |
| R-4 | Very Scarce | (Tens of Thousands) |
| R-5 | Rare | (Several Thousand) |
| R-6 | Very Rare | (Several Hundred) |
| R-7 | Extremely Rare | (Few Tens) |
| R-8 | Unique or
Nearly Unique | (Several) |
A plus sign (e.g. R-6+) indicates a higher degree of rarity