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