Sapphire
4 of the 7 encyclopedias on this shelf carry an entry for Sapphire. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a gem excelled in value by no precious stone except the diamond, and regarded as a variety of corundum, highly transparent and brilliant. It is sometimes colorless or nearly so. It more frequently exhibits exquisite color, generally a bright red (i. e., the ruby) -the latter being that or a beautiful blue commonly called sapphire. Purplish or color indicates a flaw; and greenish usual defects are clouds, milky spots, flakes, or stripes. It is found crystallized, usually in six-sided prisms, terminated by by six-sided pyramids; it is sometimes found imbedded in gneiss, but more frequently occurs in alluvial soils. It occurs in Bohemia and Saxony, but European sapphires are of no commercial importance. The finest are found in Ceylon; Kashmir and Burma also produce fine specimens; and sapphires are found in Victoria, New South Wales, and parts of the United States. The value depends on quality more than on size, and does not increase with the size as does the ruby.
Aiton's Encyclopedia (1910)
saf'ir, a beautiful, transparent, precious stone. It is a form of corundum. It is akin to the red ruby, but differs from it in being of a blue color. A yellow sapphire is known as a topaz; a green, as an emerald; a violet as an amethyst. The finest sapphires are perhaps those of Ceylon, Cashmere, and Siam. Beautiful sapphires are obtained from Queensland, Australia. Sapphires of a rich, delicate blue color are found in the gold-bearing gravels of Montana. The sapphire owes its beauty to a quality akin to phosphorescence. See Corundum ; Ruby Now glowed the firmament with living sapphires. Milton, Paradise Lost .
An Encyclopaedia of Occultism (1920)
It is understood to make the melancholy cheerful and maintain the power or manly vigour of the body. The high priest of Egypt wore a sapphire upon his shoulder, and Aelian says that it was called truth. The Buddhists still ascribe a sacred magical power to it, and hold that it reconciles man to God. It is a good amulet against fear, promotes the flow of the animal spirits, hindereth ague and gout, promotes chastity, and prevents the eyes from being affected by small-pox. Sara, St., of Egypt: (See Gypsies .)
The Encyclopedia of Founding (1892)
A precious stone, almost equal to the diamond in hardness. It is highly transparent and brilliant, and consists of nearly pure alumina or clay, with a minute portion of iron. White sapphire resembles the diamond. Red sapphire is called the oriental ruby; blue being the common sapphire of the ancients, and yellow the oriental topaz. See PRECIOUS STONES.