- Joined
- Apr 12, 2021
- Messages
- 1,165
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- Location
- Boston-Metrowest
- What state or country do you live in
- Massachusetts
A close-up picture under white lights of the "diatoms" in question would be helpful. Given the descriptions, I'm not so sure they're actually diatoms. Could be dinos. Do you see anything on the rocks? Do you see any air bubbles trapped inside it?

