How to tell regular issue from SMS coins?

TWQG

I've got a regular issue 1967 Washington Quarter with neat toning that I've only seen on SMS coins. Is there some sure way to make the diagnosis?

mbbiker

get it graded?

TWQG

PCGS MS67 (far from a sure diagnosis)

cladking

This is a frequent question here and there has been no definitive answer. Almost every
SMS coin looks better than almost every circulation strike, but this is no real help.

mbbiker

i always thought that PCGS put SMS on the slab if it was a true SMS coin, am i wrong?

cladking

It appears that if a coin has the look of an SMS that it is graded as an SMS, and that
if it has the look of a production issue they are graded MS. This is probably accurate
in the majority of cases. Also keep in mind that most of the SMS coins were technically
minted the same as regular production strikes, ie- struck once on standard planchets.
So for most practical purposes there is no difference between the bulk of the SMS coins
and the rest except for the look. SMS dies were in some cases retired to strike regular
issue coins and some of these do look SMS. There were at least a few different SMS dies
used so even all the SMS coins don't look the same. One of these dies was a regular
production die polished to a high gloss and then struck on a polished planchet. These
coins are extremely unattractive but are often found with no marks! There is a wide
range of coin types made during this era and few can be definitively shown to be SMS and
perhaps none to be regular production strikes.