In the book of Moses, God designated the carbuncle gemstone to lie first in the second row of the Breastplate of Judgement, representing the Tribe of Levi.
St. Albert the Great tells us that through meditation with God, the virtues of the carbuncle stone helps it's wearer to:"dispel sorrow and gladden the heart," with God's permission; thus, encouraging it's bestowed to pray fervently for an increase in the virtues of faith, hope & joy.
-The virtues of the carbuncle stone from St. Albert the Great's medieval treatise,De Mineralibus