|Easton's Bible Dictionary|
(1.) A precious gem (Hebrews yahalom', in allusion to its hardness), otherwise unknown, the sixth, i.e., the third in the second row, in the breastplate of the high priest, with the name of Naphtali engraven on it (Exodus 28:18; 39:11; R.V. marg., "sardonyx.")
(2.) A precious stone (Hebrews shamir', a sharp point) mentioned in Jeremiah 17:1. From its hardness it was used for cutting and perforating other minerals. It is rendered "adamant" (q.v.) in Ezek. 3:9, Zechariah 7:12. It is the hardest and most valuable of precious stones.
Noah Webster's Dictionary
1. (n.) A precious stone or gem excelling in brilliancy and beautiful play of prismatic colors, and remarkable for extreme hardness.
2. (n.) A geometrical figure, consisting of four equal straight lines, and having two of the interior angles acute and two obtuse; a rhombus; a lozenge.
3. (n.) One of a suit of playing cards, stamped with the figure of a diamond.
4. (n.) A pointed projection, like a four-sided pyramid, used for ornament in lines or groups.
5. (n.) The infield; the square space, 90 feet on a side, having the bases at its angles.
6. (n.) The smallest kind of type in English printing, except that called brilliant, which is seldom seen.
7. (a.) Resembling a diamond; made of, or abounding in, diamonds; as, a diamond chain; a diamond field.
Int. Standard Bible Encyclopedia
di'-a-mund. See STONES, PRECIOUS.
Diamond (5 Occurrences)
Exodus 28:18 And the second row shall be an emerald, a sapphire, and a diamond. (KJV ASV DBY WBS YLT NAS RSV)
Exodus 39:11 And the second row, an emerald, a sapphire, and a diamond. (KJV ASV DBY WBS YLT NAS RSV)
Jeremiah 17:1 The sin of Judah is written with a pen of iron, and with the point of a diamond: it is engraved on the tablet of their heart, and on the horns of your altars; (WEB KJV JPS ASV DBY WBS YLT NAS RSV)
Ezekiel 3:9 Like a diamond harder than rock I have made your brow: have no fear of them and do not be overcome by their looks, for they are an uncontrolled people. (BBE)
Ezekiel 28:13 Thou hast been in Eden the garden of God; every precious stone was thy covering, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created. (KJV ASV BBE DBY WBS YLT NAS)