Cormac McCarthy is one of many authors known to make up words, either by sticking two separate words together, or by using them in unusual ways. This is one example.
Murrhine means of, relating to, or made of murra, which is a material thought to be of semiprecious stone or porcelain used to make costly vessels in ancient Rome. But this isn’t exactly how McCarthy uses the word.
Instead he uses it as a verb, murrhined. You can think of this in the same way the word stoned can be used to describe someone who has been turned to stone.
Here is the sentence, yet again from The Orchard Keeper, describing a burning building:
“There it continued to burn, generating such heat that the hoard of glass beneath it ran molten and fused in a single sheet, shaped in ripples and flutings, encysted with crisp and blackened rubble, murrhined with bottlecaps.”
Jonas David 