Onyx. Chalcedony in parallel layers of different shades of color. It is used for making cameos, the figure being cut in one layer with the next layer as a background. It is stained black and used to make mourning jewelry.
“It is most profitable, it is blessed, to be always looking beyond second causes in all our trials and distresses, and to discern the Lord's hand, in infinite love and wisdom, appointing all. For this brings the soul into a state of resignation and tranquility at least, if not of holy Joy.”
–Robert Hawker, Poor Man’s Commentary, Psalm 17