They were talking about "Herkimer Diamonds," which of course aren't actually diamonds at all, but double-terminated quartz found in the Herkimer County region of New York state. I had never heard of this and so joined the conversation.
Herkimer diamonds were first discovered by workmen while cutting into the Mohawk River Valley dolostone in the late 18th century. While they are not "real" diamonds, these beautiful gemstones from New York State are often known for their extreme clarity.
(c) 2009 - Ruth Mitchell - all rights reserved