Baetylus (also Baetyl, Bethel, or Betyl, from Semitic bet el "house of god") are sacred stones that were supposedly endowed with life. According to ancient sources, these objects of worship were meteorites, which were dedicated to the gods or revered as symbols of the gods themselves.
In the Phoenician mythology related by Sanchuniathon, one of the sons of Uranus was named Baetylus. The worship of baetyls was widespread in the Phoenician colonies, including Carthage, even after the adoption of Christianity, and was denounced by Augustine of Hippo.
In ancient Greek religion and mythology, the term was specially applied to the Omphalos, symbolising the pineal gland of the brain,  the stone supposed to have been swallowed by Cronus (who feared misfortune from his own children) in mistake for his infant son Zeus, for whom it had been substituted by Gaea. This stone was carefully preserved at Delphi, anointed with oil every day and on festive occasions covered with raw wool.
In Rome, there was the stone effigy of Cybele, called Mater Idaea Deum, that had been ceremoniously brought from Pessinus in Asia Minor in 204 BC. Another conical meteorite was enshrined in the Elagabalium to personify the Syrian deity Elagabalus.
In some cases an attempt was made to give a more regular form to the original shapeless stone: thus Apollo Agyieus was represented by a conical pillar with a pointed end, Zeus Meilichius in the form of a pyramid.
According to Tacitus, the simulacrum of the goddess at the temple of Aphrodite Paphia at her mythological birthplace at Paphos, on Cyprus, was a rounded object, approximately conical or shaped like a meta (a turning post on a Roman circus) but "the reason for this" he noted, "is obscure".
Other famous baetylic idols were those in the temples of Zeus Casius at Seleucia Pieria, and of Zeus Teleios at Tegea. Even in the declining years of paganism, these idols still retained their significance, as is shown by the attacks upon them by ecclesiastical writers.