Agate
3 of the 7 encyclopedias on this shelf carry an entry for Agate. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
a mineral classed by Dana bronze that composite metal became known, and began to be manufactured into weapons and other instruments; while, under the same category being when the age of iron came in, bronze began gradually to be superseded by the last-mentioned metal. (Lyell's "The Antiquity of Man"; Lubbock's "Prehistoric Times.") In Law, the time of competence to do certain acts. In the United States, both males and females are of full age at 21. The age at which minors may be punished or may marry varies in the several States. Age of Animals. The duration of life in animals is generally between seven and eight times the period which elapses from birth till they become adult; but this rule, besides being vague and indefinite, is quite useless in practice, because it affords no scale of graduation which would enable us to ascertain the pr precise age of individuals. Age of Plants. Plants, like animals, are subject to the laws of mortality, and, in many cases, have the period of their existence determined by nature with as much exactness as that of an insect. It is principally to annual and biennial plants that a precise period of duration is fixed. The remainder of the more perfect part of the vegetable kingdom, whether herbaceous, or shrubby, or arborescent, consist of plants which may be classed under two principal modes of growth. One of these modes is to increase, when young, in diameter, rather than in length until a certain magnitude is obtained, and then to shoot up a stem, the diameter of which is never materially altered. The addition of new matter to a trunk of this kind takes place by the insinuation of longitudinal fibers into the inside of the wood near the center; on which account such trees are called endogenous, or monocotyledons. The other mode is, from the beginning, to increase simultaneously in length and diameter, but principally in length. The addition of new matter to a trunk of this kind takes place by the insinuation of longitudinal fibers into a space beneath the bark, and on the outside of the wood, near the circumference; on which account such trees are called exogenous, or dicotyledons. The way by which the age of exogenou trees may be computed is by cutting out a portion of their circumference, and counting the number of concentric rings that are visible; the woody cylinder of one year being divided from the succeeding one by a denser substance, which marks distinctly the line of separation of the two years. In consequence of the extreme inequality in thickness of the annual layers of wood on opposite sides of a stem, a person judging of the whole age of a tree by the examination of the layers of the stunted side only would commit errors to the amount of 60 per cent., and more.
Aiton's Encyclopedia (1910)
ag'at, a variety of quartz peculiarly composed of many bands or layers of different colors. It is related to chalcedony, carnelian, and onyx. The moss agate owes its appearance to a peculiar moss-like stain of manganese or iron-oxide, spreading and branching like frost on a window pane. The name "mocha stone," sometimes applied to moss agates, is either due to the fact that those first used came from Mocha in Arabia, or it is a corruption of "moss agate." While the finest moss agates are obtained from India, they are found in many localities in the states of Utah, Wyoming, Colorado, and Montana. Very fine agates are found near Oldenburg in Germany. The best occur as rolled pebbles in the beds of streams. Kunz remarks that "no stone that is used in jewelry in the United States is cheaper, more beautiful, or more plentiful than the moss agate." Cloudy agates, stone agates, and the like, are names of other varieties. Agates make very attractive ornaments, and are used in rings and seals, in the handles of knives and forks, toilet articles, button hooks, and the like, or for beads, marbles, etc. On account of their hardness, agates make excellent watch jewels and bearings for pivots and scales. Gold wire is drawn through an agate eye. In Scotland agates are known as "Scotch pebbles." The British Museum possesses a peculiar Egyptian agate bearing an accidental likeness to the face of the poet Chaucer. Variegated Agate Band Agate Agate Lake Superior. Moss Agate. Clouded Agate Banded Agate (Brazil) Bloodstone March. Agate June. Sapphire September. Turquoise December. Birthstones Amethyst February. Emerald May. Sardonyx August. Topaz November. Birthstones Garnet January. Diamond April. Ruby July. Opal October. Birthstones 2026 Editor's Note: Agate lent its name to two everyday t hing s that outlived the stone's fame: the 'aggie' marbles children prized, and 'agate type,' the tiny 5.5-point font still behind newspaper stock tables and box scores — a sports editor's 'agate' to this day. Most brightly colored agate sold now is dyed. (Ed: BR 2026-07-13)
The Encyclopedia of Founding (1892)
This stone is an aggregate of siliceous substances, the character and color of which is maintained in the mass. Agate is composed of chalcedony, quartz, amethyst, carnelian, jasper, common opal, etc., with all their varying colors. Its hardness and beauty have brought it into great demand both for useful and ornamental purposes. See STONE; PRECIOUS STONES.