A natural shiny and smooth white and cream clam shell-shaped shell necklace. The necklace has a total measurement length of 17" and has a working screw barrel clasp. The condition is good.
This does not appear to be a Puka shell and has more of the coloring of a Luhunaus shell so I am not confident to make an exact determination on what kind of shell necklace this is.
To measure the best necklace size for you, take a tape measure and wrap around your neck to get its circumference. Take that number and add 2" to 4" to determine the best minimum necklace length for you. For a regular necklace, choose the second size up from your neck size as a minimum. For example, if your neck measures 15" around, the minimum necklace size you should choose would be 17" to 19". If you want a choker, stick with your exact neck measurement for the necklace size. Standard necklaces sizes, common to most people, come in the following sizes: