Was known to the Egyptians at a very early period of their national history, at least B.C. 1500. Various articles both useful and ornamental were made of it, as bottles, vases, etc. A glass bottle with the name of Sargon on it was found among the ruins of the north-west palace of Nimroud. The Hebrew word zekukith (Job 28:17), rendered in the Authorized Version "crystal," is rightly rendered in the Revised Version "glass." This is the only allusion to glass found in the Old Testament. It is referred to in the New Testament in Revelation 4:6; 15:2; 21:18, 21. In Job 37:18, the word rendered "looking-glass" is in the Revised Version properly rendered "mirror," formed, i.e., of some metal. (Comp. Exodus 38:8: "looking-glasses" are brazen mirrors, R.V.). A mirror is referred to also in James 1:23.

Noah Webster's New International Dictionary of the English Language

1. (n.) A hard, brittle, translucent, and commonly transparent substance, white or colored, having a conchoidal fracture, and made by fusing together sand or silica with lime, potash, soda, or lead oxide. It is used for window panes and mirrors, for articles of table and culinary use, for lenses, and various articles of ornament.

2. (v. t.) Any substance having a peculiar glassy appearance, and a conchoidal fracture, and usually produced by fusion.

3. (v. t.) Anything made of glass.

4. (n.) A looking-glass; a mirror.

5. (n.) A vessel filled with running sand for measuring time; an hourglass; and hence, the time in which such a vessel is exhausted of its sand.

6. (n.) A drinking vessel; a tumbler; a goblet; hence, the contents of such a vessel; especially; spirituous liquors; as, he took a glass at dinner.

7. (n.) An optical glass; a lens; a spyglass; -- in the plural, spectacles; as, a pair of glasses; he wears glasses.

8. (n.) A weatherglass; a barometer.

9. (v. t.) To reflect, as in a mirror; to mirror; -- used reflexively.

10. (v. t.) To case in glass.

11. (v. t.) To cover or furnish with glass; to glaze.

12. (v. t.) To smooth or polish anything, as leather, by rubbing it with a glass burnisher.