Hi Ellen, Yes, suspending the shell in a liquid sounds right. Otherwise the spines will inevitably get chipped when the vial knocks against something. It would have to be a fairly viscous liquid in order to provide such protection, and obviously something that will not react with the shell. Mineral oil sounds like a good bet. It also has good optical properties, so will allow clear viewing of the shell without distortion (of course, the curvature of the glass will cause some distortion, but that can't be helped if you are going with a round vial (perhaps a flat-sided vial - square or traingular - would be an option?). Whether the shell will float due to entrapped air is uncertain. A lightweight shell like a small Cypraea, Melampus, or bubble shell would definitely float in mineral oil unless interior air was removed. A solid shell like a Drupa or Morula definitely would not float, even if filled with air. A shell of intermediate weight and limited interior space - like a Typhis - could go either way. Interior air can be removed from a small shell by exposure to vacuum, as described in a recent post on cleaning shells. Paul M.