King James Bible Dictionary

1. A precious gem (Heb. 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 (Heb. 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 Ezekiel 3:9, Zechariah 7:12. It is the hardest and most valuable of precious stones.

One of the jewels in the breastplate.
Exodus 28:18; Exodus 39:11; Jeremiah 17:1; Ezekiel 28:13

(Heb. yahalom), a gem crystallized carbon, the most valued and brilliant of precious stones, remarkable for its hardness, the third precious stone in the second row on the breastplate of the high priest, (Exodus 28:18; 39:11) and mentioned by Ezekiel, (Ezekiel 28:13) among the precious stones of the king of Tyre. Some suppose yahalom to be the "emerald." Respecting shamir , which is translated "Diamond" in (Jeremiah 17:1) see under ADAMANT.

DIAMOND, noun Dimond. [Latin , Gr. See Adamant.]

1. A mineral, gem or precious stone, of the most valuable kind, remarkable for its hardness, as it scratches all other minerals. When pure, the diamond is usually clear and transparent, but it is sometimes colored. In its rough state, it is commonly in the form of a roundish pebble, or of octahedral crystals. It consists of carbon, and when heated to 14 degrees Wedgewood, and exposed to a current of air, it is gradually, but completely combustible. When pure and transparent, it is said to be of the first water.

2. A very small printing letter.

3. A figure, otherwise called a rhombus.

DIAMOND, adjective Resembling a diamond as a diamond color; or consisting of diamonds, as a diamond chain.

DIAMONDED, adjective Having the figure of an oblique angled parallelogram, or rhombus.

DIAMOND-MINE, noun A mine in which diamonds are found.