Micro diamonds?

[Gregyem]

I have been looking through some heavy fines I brought home and panned these interesting pieces from them. They are all less than a millimeter across. The spheres are magnetic (magnetite or ilmenite maybe I really don't know). The crystals are pretty warn so shape is not that obvious but turning them under the lens at least six of them are octahedrons. None have six sides, so I am ruling out quartz. Do I have tiny diamonds or am I being conned by topaz or zircon imposters?

 

[Moneybox]

Diamonds are not uncommon but they are usually so far between that it's not commercially viable to mine them.

 

[user 4386]

Specific gravity is quite diagnostic - lower in diamond. Diamond is much harder