Probably the ancient topaz of a golden colour. Re 21:20. The Greek word ?????????? occurs in the LXX in Ex 28:20; 36:20 (Ex 39:13); Eze 28:13.
the fifth, sardonyx; the sixth, sardius; the seventh, chrysolite; the eighth, beryl; the ninth, topaz; the tenth, chrysoprasus; the eleventh, hyacinth; the twelfth, amethyst.