For those asking about the illustrations of the Eagle diamond (this post's fifth image):
The five views of the Eagle diamond that appeared in "Emigrant Diamonds in America" by Prof. William Herbert Hobbs, published in Appleton's Popular Science Monthly, vol. LVI (November 1899; page 75), were drawn by American mineralogist and mineral collector George Frederick Kunz (Sep. 29, 1856-June 29, 1932).
Tiffany & Co. hired 23-year-old, self-taught George F. Kunz as the American luxury jewelry and specialty design house's chief gemologist in 1879. He served as a Tiffany vice-president from 1907 until his death in 1932. Kunz was "America's first gemologist" and "arguably the world’s foremost gemologist and mineralogist to ever live," according to author and meteorite and tektite collector Mitch Noda in "George F. Kunz and Tiffany and Company," published Jan. 1, 2024, in Meteorite Times magazine.
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https://www.meteorite-times.com/george-f-kunz-and-tiffany-and-co/)