The Breastplate of Aaron is of interest to crystal lovers because it is an early account of the use of crystals for both symbolic and decorative reasons.
The Breastplate of Aaron, who was High Priest of the Hebrews and brother of Moses, was of great importance because by means of it, God revealed his Divine will to His chosen people.
It was designed by God Himself and the directions as to how it was to be made were given to Moses (as illustrated in Exodus 28.) The original association of a special gem with each month was recorded in the Bible (Exodus 28 and 39).
The twelve gems in the breastplate were later linked with the Signs of the Zodiac and later still, associated with the months in the year. Upon the breastplate were set four rows of precious stones, three in each row, and upon them were engraved the names of the 12 tribes.
In the first row there is a ruby, a topaz and a beryl; in the second row a turquoise, a sapphire and an emerald; in the third row a jacinth, an agate and an amethyst; in the fourth row a chrysolite, an onyx and a jasper.
The exact identification of some of these gemstones are uncertain. For instance, it is important to realize that there are other forms of beryl such as aquamarines and emeralds.
Sardonyx is a form of onyx, and jacinth and chrysolite are also known respectively as zircon and peridot.
In the revised Standard Version of Exodus, diamonds, sardius, and carbuncle (an alternative name for the garnet) are also included in the list of twelve biblically significant gemstones.