[chiralSPO (OP)]

Phosphenes are visual artifacts, while phosphines are chemical compounds in which a phosphorus atom is bonded to three organic (or H) substituents and has a lone pair.

Humans are people, while humins are organic compounds found in the soil.

Can anybody identify other pairs of homophones between a scientific jargon term and a "normal" word, or jargon from different fields?

[Bored chemist]

The classic example in chemistry is periodic acid.
We also wonder about stuff being unionised (rather than ionised).