Silicon dioxide (sio2) and diamonds are best described as

Silicon dioxide (SiO₂) and diamonds are best described as network solids with covalent bonding.
Covalent-network solid is a chemical compound (or element) in which the atoms are bonded by covalent bonds in a continuous network extending throughout the material.  Silicon(IV) oxide has continuous three-dimensional network of SiO₂ units and diamond has sp3 hybridization.

I’d have to say no because without oxygen in the water the fish would all be dead. so if you want to fish for dead fish, pick the ponds with the lowest oxygen concentrations.