LOS ANGELES -- Four pieces of jewelry may help detectives identify the skulls of a man and a woman found in a burned-out mountain ravine of the Angeles National Forest.

Homicide detectives released photos of the jewelry on Wednesday, hoping someone will recognize the items.

The pictures show three rings, one with small ruby stones, one with emerald-green stones, and one with black stones, each with interlocking white gems in a gold-colored setting. The fourth piece is a gold-colored chain necklace.

The skulls were discovered Dec. 24 and Dec. 26 in an area of forest that was ravaged by flames during last summer's devastating Station Fire, said Los Angeles County Sheriff's Sgt. Ed Hummel.

Authorities say the man's skull had a bullet hole in it and appeared to pre-date the Station Fire, which burned 250 square miles of the San Gabriel Mountains in late August and September.

"Just from the condition of the skull, it sounds like it was skeletonized before the fire. It's definitely a skull, not attached to the body," said Los Angeles County Coroner's Investigator Jerry McKibben.

The woman's skull also showed signs of trauma, according to authorities.

A coroner's spokesman said the causes of death have been officially "deferred," pending more scientific testing.

Both sets of remains have not been identified. Investigators say the skulls may have been there for months, even years, before the fire.

Detectives have not said when the rings and necklace were discovered, only that they were found where the skulls and other remains were located.

Homicide investigators urged anyone with information on the remains to call Detective Philip Guzman or Detective John Duncan at (323) 890-5500.