CO, CO2, carbonate salts like Na2CO3, or CaCO3, and cyanides like HCN, NaCN, and KCN are usually considered inorganic compounds instead of organic compounds, despite containing carbons. But the vast majority of carbon-containing compounds are considered organic, and there are no organic compounds that don't contain carbon.
> there are no organic compounds that don't contain carbon
It's very much nitpicking and an edge case but now you've got me wondering if some silicone hydrocarbon analogs might not qualify. Noting that we have plausible theories about the feasibility of silicone based life.
I mean, I don't think diamonds are considered "organic"; same for graphite. But that's where the term "organic" itself starts to break down as a category.
Wikipedia: "Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials (i.e. matter in its various forms that contain carbon atoms)."
It doesn't break down at all. Diamonds are organic structures, in the classical definition of that term. (Assuming they weren't treated with insecticides in the mine... /s)
I don't think wikipedia is the best reference here, and I think you're also misinterpreting them; not all carbon-containing substances (including diamond) are considered organic. There is no true classical definition of the term- it's actually a fairly nebulous concept. Ultimately you're just arguing about definitions which is not particularly interesting.