Ancient Greek and Roman artifacts are, well, old. When some things become old, they become brittle and fragile, breaking more easily. As well, external factors like sunlight, erosion, water, and wind can effect artifacts. It also depends on where the artifacts are from- if they were from the city of Pompeii, for example, they could have been physically broken by rock, buried by the buildings they were in, or shattered by the tremors of Mount Vesuvius.
If You are talking about greek an roman gods, it is roman.
The Roman is Nereus; the Greek is Νηρευς
Apollo is Greek god not Roman.
Hephaestus is a Greek god not Roman.
Pegasus is both Greek and Roman.
It is a Greek myth if written by a Greek in Greek, or stated to be originating with the ancient Greek people. It is a Roman myth if written in Latin by a Roman citizen.
Persephone (Greek) Proserpine/Proserpina (Roman)Pan (Greek)Poseidon (Greek)Pluto (Roman)
Zeus was Greek. Jupiter was Roman.
Roman. Venus's Greek counterpart is Aphrodite.
Saturn is a Roman god not greek
Hera(Greek) Juno(Roman)
The blend of Greek and Roman cultures is referred to as Greco-Roman.