Yashfeh - Jasper
Gem of the Tribe of Binyamin
Yashfeh (Jasper), a multi-colored stone consisting of red, black and green.
This stone stopped bleeding (Rabbi Bachya on Shemot 28:15) and designated for the Tribe of Binyamin because Binyamin knew that his brothers had sold Yosef, but did not tell his father and therefore prevented bloodshed.
The shoham and the yashfeh were placed on the Choshen (breastplate) worn by the Kohen Gadol (High Priest) Aharon when he entered the HaKodesh (The Holy Place) as a remembrance before G-d. (Shemot 28:29)
The name of Binyamin was engraved on the yashfeh.
"Binyamin had many contradictory thoughts about the sale of Yosef by his brothers, all of which are reflected in the different colors of the jasper. The reason the gemstone was assigned to the tribe of Binyamin had to do with the founder of that tribe not being able to decide if to tell his father that Yosef was most likely alive, or to keep silent as he could not foresee how Yaakov would react to such information. In the end he controlled himself, stopped himself, and di not reveal what he knw. The yashfeh may be understood as two words, i.e. `yesh peh', "he has a mouth," or words to that effect. The name of that stone alludes to the fact that Binyamin deserved credit for keeping silent about what he knew his brothers had done to his older brother Yosef." (Rabbeinu Bachya - Shemot 28:15)