The Type I SBA dollars, because of their premium coinciding with the ease of production, have been counterfeited.  The difficulty is that the main criteria for determining these counterfeits is their respective weights.

The circulating counterfeits are cast and weigh about 8.7 grams.  The genuine coins only weigh 8.1 grams.

Don't have a sensitive scale that can detect a half of a gram?

Try this:

Balance a later date SBA dollar on your finger tip and tap it with another coin.  It will have a ring to it.  Then, do the same with the 1979 coin in question and see if it has a similar ring.  If so, it is probably genuine.  If not, if in fact it has a rather dull sound, then it is probably a counterfeit.

In addition to the ring test, the counterfeit will show raised bubbles on the surface.  See the issue of Coin World, May 28, 1986, page 82 for photos.

If you have any information on this coin, I would like to hear from you.

Byron Behrens