White Spots on 1921 D Morgan

[Hack]

This 1921 D graded MS65 has white spots in the field. What is the typical cause of the white spots?

 

[Walkerfan]

Usually happens after a dip. Residue and discoloration from an improper rinse or else remnants of some of the silver patina remaining.

[coinman1794]

While it is possible this piece has been dipped at some point, milk spotting, like that seen here, is ubiquitous on silver dollars between 1921 and 1935. Some have speculated that the planchets were rinsed a different way that in years past, causing the milks spots often encountered. Often, the spots are struck into the surface or are otherwise etched into the coin such that a dip will not remove them.

[RWB]

Incomplete rinsing after the whitening bath. Very common on all the Pittman silver dollars due to the haste in which they were made.

 

See From Mine To Mint for details of the chemicals used, etc.

[blu62vette]

I agree very common for the date and so common it just gets overlooked.

 

I cant stand them. I have 5 PL's and one DMPL for 1921 (not D or S) and none have spots. It has been hard finding that many without spots.

[david3142]

Sounds like you have some extras you need to sell.

 

I think the grading services are a little more forgiving of 1921 Morgans as well, and not just with regards to spotting.

[RWB]

PS: The spots are difficult to remove because they were surface contamination on the planchet. During striking, pressure, metal deformation and heat often bond the contaminant into the surface. It would be much the same with copper oxide or other particulates.

 

[Hack]

RWB,

 

Most of 1921 Morgans have a different type of luster, than, pre 1921 Morgans. On the 1921's the luster looks broken and not consistent on the fields much like that is seen on the Peace dollars. What caused the luster difference in the 1921 series?

[messydesk]

The luster is actually different between the three mints for 1921 Morgans. 21-P tends to look the frostiest to me, 21-D not as much, and 21-S has lots of "orange peel" luster coins due to bad die erosion. The other cause of the difference between the luster on 1921 coins and previous ones is the major change in the design. Both sides are lower relief, so the metal flow characteristics, which cause the flow lines on the dies that give us luster, were different.

[RWB]

Much as messydesk noted. Also different die steel was in use by 1920 and planchet treatment was also different.

[physics-fan3.14]

Many 20th century coins exhibit these spots, not just Pittman coins. The Franklin series is well known for them (well, among the half dozen people who collect them ).