Not knowing where it was found it (country, surroundings, etc.) it could be anything from the decorations at the mermaid hole at a miniature golf course to a statue of Triton for a water garden.
Some cultures use conch shells as grave markers. Hindu and Buddists consider it a symbol of strength ("Shankha") as Vishnu used it for his war trumpet and the Buddists consider it symbolic of sound and teeth.
As a rule of thumb cement is not used for significant work.