This 10mm cone is one of three tiny cones taken in coral rubble off of Kauai.  I thought them to be C. abbreviatus juveniles due to the brown dots and bluish color but I posted them on another site and they said it was C. sponsalis.  It doesn't look like sponsalis I've seen online.

This specimen is the only one I could get clean enough to see the markings well.

Hi there. Yes, it is Conus sponsalis and the bluish colour and small brown dots identify it as form nanus. According to Rockel, Korn & Kohn specimens from Hawaii and S.E.Polynesia consistently occur in this form. Incidentally, some authors consider nanus to be a true species but intergrades are known.
Dave