Tom, I ask my wife about her Jet Jewellery and she said it became very popular during the civil war and was cheap. She said Jet was lignite (a hard coal) and was either black or a very dark brown. I think in the letter James was going to send Lizzie a small pair of jet earrings and the term Confederate Diamonds was an inside joke between James, the uncle and Lizzie, his niece. And since he says in the letter that she had never seen any before. He was messing with her and had her thinking he was sending or going to bring her some little pieces of coal called "Confederate Diamonds". This is my best guess. Oh yes my wife said she had never heard of Jet Jewellery from the war being called confederate diamonds. Again this sounds like it may have been used as an inside joke or a rarely used term in the South. Maybe another reference between Jet Jewellery and Confederate Diamonds will show up. I ask my wife how much of this Confederate Diamonds do you have, and she want say, only that its in the bank's lock box with my Confederate Buckles. R.D.