"The unicorn could escape if he wished. Clearly, however, his confinement is a happy one, to which the ripe, seed-laden pomegranates in the tree—a medieval symbol of fertility and marriage—testify. The red stains on his flank do not appear to be blood, as there are no visible wounds like those in the hunting series; rather, they represent juice dripping from bursting pomegranates above. Many of the other plants represented here, such as wild orchid, bistort, and thistle, echo this theme of marriage and procreation"

The Pomegranate.

Middle English (in sense 2): from Old French charbuncle, from Latin carbunculus ‘small coal’, from carbo ‘coal, charcoal’.

The atomic number for Carbon is 666

This bird which flies by night without wings, which the early dew of heaven, continually acting by upward and downward ascent and descent turns into the head of a cow, then into the tail of a peacock and afterwards it acquires the bright wings of a swan, and lastly redness, an index of it's fiery nature"

"I found a certain stone, red, shining, transparent and brilliant, and in it I saw all the forms of the elements and also their contraries"

The Lapis is a synonym for The carbuncle.