1. kadkod, ἴασπις: from the root to strike fire, and hence a "sparkling gem, ruby." (Ges.) "A shining, sparkling precious stone, probably a carbuncle, so called from its red sparkling colour." (Fürst.) It occurs but twice: Isaiah 54:12 , "I will make thy windows of agates." This might be thought to signify that the agate was transparent, and that the windows were to be 'glazed' with agates; but windows were not then glazed. Others translate the word 'minarets, pinnacles, battlements,' and instead of ' agates' many prefer rubies. The other passage is Ezekiel 27:16 : Syria was thy merchant for coral, the agate, etc.; they came from Damascus. The Revised Version and others again translate 'rubies' which well agrees with the signification of the word.
2. shebo, ἀχάτης, achates, Vul., from 'to burn, to glow.' (Fürst.) "A composite stone formed of quartz, chalcedony, cornelian, flint, jasper, etc. and therefore glittering with different colours." (Delitzsch.) Bochart traces the word to a root signifying 'to be spotted.' This gem has been described as a semi-pellucid, uncrystallized variety of quartz; it is found in parallel or concentric layers of various colours, and presents different tints in the same specimen. It is generally, translated 'agate.' It was the stone chosen for the second place in the third row of the breastplate of the high priest. Exodus 28:19; Exodus 39:12 .