On 31 Jul 2003 04:25:45 -0700, (High Plains
Writer) wrote:

The plastic around the coins is hard, right? Hard
plastic is not usually a problem with silver coins. The soft plastic
is. The plasticizer is PVC (poly vinyl chloride -- correcly written
as one long word) which breaks down with time, with heat, etc.

This is not correct. The *plastic* is PVC, polyvinyl chloride,
commonly called vinyl. The *plasticizer* -- another chemical or more
than one chemical (phthalates)-- is added to the PVC to make it soft.
Not always -- not in PVC pipes, for instance. But always when the
plastic is soft when it's made of PVC. PVC is not a plasticizer, it's
a plastic. And it's the plasticizer, or softeners, that primarily
cause PVC damage in coins, breaking down over time. PVC itself is very
durable, hence its use in construction, medicine, the automotive
industry, the toy industry, and so on.

And you again make an awfully definitive statement there when you say
that polyvinyl chloride is "correctly" written as poly vinyl chloride.
It's not written this way by the Vinyl Institute -- the PVC industry's
trade association -- or by Merriam-Webster's Collegiate Dictionary,
the American Heritage Dictionary of the English Language, Cambridge
International Dictionary of English, Oxford Paperback Dictionary and
Thesaurus, or Encyclopaedia Britannica.

--

Coin Collecting: Consumer Guide: http://rg.ancients.info/guide
Glomming: Coin Connoisseurship: http://rg.ancients.info/glom
Bogos: Counterfeit Coins: http://rg.ancients.info/bogos