2. It's a Haz Mat sticker (hazardous materials). It's not a secret, almost
any fireman or police officer could tell you what it stands for. I'm not
either, but basically they are a  diamond most often with 4 smaller diamonds
contained within. The smaller diamonds, red, yellow, white and blue, contain
information about the hazardous material contained within such as
volatility. There is a book, standard issue to most emergency personnel,
listing the values (and dangers) for most hazardous substances.

1. I don't know, maybe a moon snail egg case?

Russ Webb