Beryl
3 of the 7 encyclopedias on this shelf carry an entry for Beryl. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
a well known precious stone. It is composed of silicon, glucinum, oxygen, and aluminum. Beryl crystals are six-sided. Usually they are pale green, but the color may be blue, yellow, white, or light red. Add a tinge of chromium and beryl becomes genuine emerald. Aquamarine is also a variety of beryl. Beryl crystals are found in granite. They vary in size from that of a kernel of wheat to stones beyond the lifting power of the strongest man. Two enormous but coarse specimens from the granite of Grafton, New Hampshire , weigh 2,900 and 5,000 pounds each. The finest crystals come from Brazil, Ceylon, Siberia, and China. The mountains of North Carolina yield beautiful crystals. 2026 Editor's Note: Beryl's hidden asset is the metal locked inside it. Beryllium is exceptionally light, stiff and stable in cold — which is why the eighteen hexagonal mirror segments of the James Webb Space Telescope, folded up and launched in 2021 to look at the earliest galaxies, are made of gold-coated beryllium. (Ed: BR 2026-06-24)
Collier's New Encyclopedia (1921)
a colorless, yellowish, bluish or less brilliant green variety of emerald, the prevailing hue being green of various shades, but always pale. The best beryls are found in Brazil, in Siberia, and Ceylon, and in Dauria, on the frontiers of China. Beryls are also found in many parts of the United States. Some of the finer and transparent varieties of it are often called aquamarine.
The Encyclopedia of Founding (1892)
A mineral of great hardness occurring in green and bluish-green six-sided prisms. It is ranked among the gems, and is nearly identical with emerald, but is not so brilliant in color. It is infusible; with borax it fuses into a transparent glass. Its composition is: silex 68, alumina 15, glucine 14, lime 2, oxide of iron 1. See EMERALD; PRECIOUS STONES.