Hi @denise-porcello, I can’t really make out what you’ve got in the first photo. The second one looks like ‘shell hash’, which basically means a bunch of shell material compressed together. The third photo is an inorganic mineral (maybe phosphate). The last one could be part of a dugong bone, but also might be a rock (I’m leaning towards it being a rock).
Sorry it took me a little while to respond, just got back from Nebraska!