And thou shalt make a breastplate of judgment, the work of the skilful workman;

like the work of the ephod thou shalt make it: of gold, of blue, and purple,

and scarlet, and fine twined linen, shalt thou make it.

16: Four-square it shall be and double: a span shall be the length thereof,

and a span the breadth thereof.
17: And thou shalt set in it settings of stones,four rows of stones: 
 

18: And thou shalt set in it settings of stones, four rows of stones:

a row of carnelian, topaz, and smaragd shall be the first row; 19: and the third row a jacinth,
an agate, and an amethyst;
20: and the fourth row a beryl, and an onyx, and a jasper; they shall be inclosed in gold in their settings.
21: And the stones shall be according to the names of the children of Israel, twelve, according to their names;
like the engravings of a signet, every one according to his name, they shall be for the twelve tribes.

 

Exodus, Chapter 39 - Pikudi
8: And he made the breastplate, the work of the skilful workman, like the work of the ephod: of gold, of blue, and purple, and scarlet, and fine twined linen.
9: It was four-square; they made the breastplate double; a span was the length thereof, and a span the breadth thereof, being double.
10: And they set in it four rows of stones: a row of carnelian, topaz, and smaragd was the first row.
11: And the second row, a carbuncle, a sapphire, and an emerald.
12: And the third row, a jacinth, an agate, and an amethyst.
13: And the fourth row, a beryl, an onyx, and a jasper; they were inclosed in fittings of gold in their settings.

We read about the Hoshen stones for the first time in chapter 28 of the Book of Exodus, Tezaveh.
It is well-known that the Torah does not have even a single gratuitous word, and therefore it is puzzling that only one chapter later, the stones are mentioned once again, and in great detail.
This teaches us about the unique importance of the stones, and how special the Hoshen stones are when we read about them in the bible and confer them the honor conferred on them by the Almighty.
It is interesting to discover the number of extensive commentaries that were written about these verses, starting with Rabbi Bachai, through Shilei Giborim, to Abraham the doctor, the Talmud, and more.

Our sages and commentators ascribed gemstones with spiritual and physical properties,
as well as tangible affects, each one of them, in his generation, beginning with the
Great Chief Cohen. Rabbi Bachai, in his commentary on the Torah (Exedus 28), said:
Each and every one of the gemstones attracts forces from above,

and glorious Midrash continues (Genesis 14): when rain falls, everything is blessed,
and every gemstone receives power and is blessed from above, and he continues:
the gemstones are the dozen stones of the Hoshen,
and all other gemstones are derived, are derivatives of the Hoshen stones.

The Holy Zohar, Rashbi "You'll find wonderments and wisdom in the 12 Hoshen stones".
Ibn Ezra, in his commentary on the Torah
(Exodus 28-29), wrote: "All the powers will be found in the annals of each stone".

In his book Midrash Talpiot, Rabbi Bachai refers to the properties of the stones, and adds a reason for each stone and each tribe – the color, powers and effects of each and every stone. Ruby for the tribe of Reuven, and according to the Midrash its properties are for the light of eyes, and it stops bleeding, strengthens the heart, and soothes anger, and he adds: "the properties of the Ruby stone - if a woman carries it with her, she never miscarries and it is good for women who find it hard to bear children. If it is ground up and then eaten and drunk, it is very beneficial for pregnancies, and it wards off plagues". In this manner, we learn the properties of the rest of the stones: