Jasper

A precious stone frequently noticed in Scripture. It was the last of the twelve inserted in the high priest's breastplate, (Exodus 28:20; 39:13) and the first of the twelve used in the foundations of the new Jerusalem. (Revelation 21:19) The characteristics of the stone as far as they are specified in Scripture, (Revelation 21:11) are that it "was most precious," and "like crystal;" we may also infer from (Revelation 4:3) that it was a stone of brilliant and transparent light, and you can find more about that here on st-takla.org on other commentaries and dictionary entries. The stone which we name "jasper" does not accord with this description. There can be no doubt that the diamond would more adequately answer to the description in the book of Revelation.