The 16 ga. silver wire I've been using was given to me by someone who said
it was "pure".  I just ordered some 14 ga. .999 myself and was surprised to
find that I couldn't tell the difference between the two in size.  So does
the 14 ga. actually last  much longer than the 16 ga. ?  ( A dollar a foot
longer!?)
Anyway, I noticed that the 14 ga. was somewhat softer than the 16, so I
figured the purity must be higher.  How does one get their silver tested? 
No jeweler or pawn shop around here could do it.
By the way, who came up with the guage numbers getting SMALLER when the
wire gets fatter?

Karen