A few days ago a schoolboy asked about black diamonds. I
inadvertently erased the message. If anybody still has the return
address perhaps you could forward the following:
"Gem Profile/2: The Second 60"
David Federman, ed
Tina Hammond, Photographer
Pub 1992 by Modern Jewelry
Vance Publishing Co.
Library of Congress 92-061786
Page 39 “Black Diamond”
Unfortunately this source provides no bibliogaraphy but it is of interest
James D. Clarkson