These old prints come from early 20th century encyclopedias and dictionaries.  Each stone and gem was illustrated to look as realistic as possible. On the first illustration it says, ‘This plate was made under the supervision of Dr. George F. Kunz, research curator of precious stones for the American Museum of Natural History, and gem expert for Messrs. Tiffany & Co. Drawn from the actual gems.’  Individually each one is beautiful, but together on the page they are candy for the eye!