This is an antique fossil in stone that has more recently been highly polished for display.
Sourced: in France
Origin: likely French area
Age: circa 1910?s
Materials: mineral formation
Size roughly: 8 x 7 x 3 cm – 3.2 x 2.8 x 1.2 inches
Weight roughly: 145g
Condition: in vintage previously displayed condition, what looks like a small 1cm crack to edge, structually sound