16. It is to be square when doubled: a span in length and a span in width.
17. You shall set in it four rows of stones. The first row shall be a sardius, a topaz, and a carbuncle;
18. the second row an emerald, a sapphire, and a diamond;
19. the third row a jacinth, an agate, and an amethyst;
20. and the fourth row a beryl, an onyx, and a jasper. They shall be set in gold filigree.