Here are 4 Bible verses about diamonds from the Old and New Testaments of the Holy Bible (King James Version), sorted from most to least relevant.
Exodus 28:18 KJV
And the second row shall be an emerald, a sapphire, and a diamond.
Jeremiah 17:1 KJV
The sin of Judah is written with a pen of iron, and with the point of a diamond: it is graven upon the table of their heart, and upon the horns of your altars;
Ezekiel 28:13 KJV
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.
Exodus 39:11 KJV
And the second row, an emerald, a sapphire, and a diamond.