Identifying 40% Ike Dollars

In case anyone has not seen it...

The Tissue Test.

Aren't all '71 and '72 S mint marks silver?

Yes

General rules

All 71-S and 72-S Ikes are 40% silver

All business strike S mint Ikes are 40% silver (There is a single 73-S business strike known on a coppernickel clad planchet.)

All 1976-S Type 2 Ikes are copper nickel clad.

Some 73-S, 74-S, and 76-S type 1 proof Ikes are clad and some are silver. They can be told apart by either the tissue test or by weight. Silver weigh 24.59 grams, clad weigh 22.69 grams

There are a few (maybe a dozen total) 1974-D and 1977-D 40% silver Ikes known. Use the tissue test and if any pass that test then check weight.

OK let's say we're at a fast paced auction.

And all we want to do is to bid on accurately identified 40% Ike 'silver' dollars.

Would the following summary statement accurate describe the procedure that could be followed to end up with the desired end result for silver Ike dollars?:

a) All '71S and '72S coins should ‘always' be 40% silver.

b) All '73S, '74S, '74D and '77D coins could either be 40% silver or a Cu/Ni alloy. (Cu = copper, Ni = nickel)

c) All 1776 - 1976 and 1776 - 1976S coins could either be 40% silver or a Cu/Ni alloy

d) The dollar coins in b) and c) above should be weighed to ensure that 40% dollar coins weigh 24.59 grams or 26.26 grams (if they are covered with a stapled white paper mylar holder)

e) The tissue test should only be used secondarily after the weight test to avoid erroneous results obtained from silver 'plated' Cu/Ni coins etc.

This is my personal interpretation after reading multiple opinions for IDing 40% 'silver' Ike dollars.

If my interpretation needs adjustments or if a faster method exists for IDing 40% 'silver' Ike dollars, I am always open for suggestions.

Remember that we are at an auction with an auctioneer that frowns upon slow and detailed buyers wanting to avoid being taken to the cleaners.

thanks,
mdpmedia

Two questions:

1) Do you agree that 1776 - 1976( no mint mark)Ike dollars can be either 40% silver or Cu/Ni clad (no silver)?

2) Should the tissue test still give accurate results if the coin is stapled shut within a clear Mylar holder or sealed within a hard plastic slab like NGC or PCGS?

Try this for fast determination. (Sorry had to use leading periods to indent the paragraphs. Forum doesn't recognize leading periods or tabs.)

1. Coin is Unc
.....1. Coin is S mint it is silver
.....2. Coin is 74-D or 77-D Do tissue test
..........1. tissue test indicates Coppernickel - not silver
..........2. tissue test indicates silver, weigh the coin.
...............1. Coin weighs 24.6 grams - Silver
...............2. Coin weighs 22.7 grams - coppernickel
.....3. Coin is coppernickel

2. Coin is Proof
.....1. Coin is 71-S or 72-S - Silver
.....2. Coin is 73-S, 74-S, or 76-S Type I do tissue test
..........1. tissue test indicates Coppernickel - not silver
..........2. tissue test indicates silver, weigh the coin. (it is probably safe to assume it is silver. I've never heard of a silver plated coppernickel proof.)
...............1. Coin weighs 24.6 grams - Silver
...............2. Coin weighs 22.7 grams - coppernickel
.....3. Coin is coppernickel

The paragraph style works very quickly because at each eliminates a lot of possibilities at each step. At the first level you decide is it an unc or proof coin. It will be one or the other and then you only have to worry about the sub-paragraph under that heading and so on.

Really glad I started this post because I've learned a ton! Thanks for the insights everyone!

mdpmedia, when in doubt just skip it.

Buy 71-s or 72-s as 40% silvers avoid the other ikes unless they boxed.

Thats my advice. Theres always more coins and more silver to be had.