Exodus 39:9

King James 3 - The Literal Traslation

it was square. They made the breastpiece double; its length a span and its width a span, doubled.

Cross References

Exodus 39:10

And they set it in four rows of stones: one row, the first row: a ruby, a topaz and an carbuncle.

Exodus 39:8

And he made the breast-piece, a work of an artisan, like the work of the ephod: gold, blue, purple, and crimson, and twined bleached linen;