Emily Dickinson Lexicon

RU'BY, n. [Fr. rubis; Sp. rubi; Port. rubi, rubim; It. rubino; D. robyn; G. Dan. and Sw. rubin; Ir. id.; from L. rubeo, to be red.]

1. A precious stone; a mineral of a carmine red color, sometimes verging to violet, or intermediate between carmine and hyacinth red; but its parts vary in color, and hence it is called sapphire ruby or orange red, and by some vermeille or rubicel. Kirwan. There are two kinds of ruby, the oriental or corundum, and the spinelle. The latter is distinguishable from the former by its color and crystalization. Phillips. The ruby is next in hardness and value to the diamond, and highly esteemed in jewelry.
2. Redness; red color. – Shak.
3. Any thing red. – Milton.
4. A blain; a blotch; a carbuncle. [The ruby is said to be the stone called by Pliny a carbuncle.] Ruby of arsenic or sulphur, is the regular, protosulphuret of arsenic, or red compound of arsenic and sulphur. – Encyc. Nicholson. Ruby of zink, is the protosulphuret of zink, or red blend. Rock ruby, the amethystizontes of the ancients, is the most valued species of garnet. – Encyc.