Is there any non-metallic oxide that remains in solid state at room temperature?

Except for metallic and semimetallic oxides, is there any oxide (non-metallic oxide) which remains in the solid state at room temperature?

• SiO2? Boron oxide? – Pieter Jan 22 '18 at 19:32
• Silicon, Boron, etc are the chemical elements whose show the properties between metal and nonmetal. Due to this exhibition of their properties, they are called semi-metal, and their oxides are semimetallic oxides. – Rakibul Hassan Jan 22 '18 at 19:40
• Under your definitions, what elements would not fall under 'metallic' or 'semimetallic'? The noble gases are clearly out, halogens are out, and you seem to reject P et al. as semimetallic, so that limits the choices on the right side of the periodic table. On the left side, one starts with metals from the get-go. – Jon Custer Jan 22 '18 at 19:58
• Would Chemistry be a better home for this question? – Qmechanic Jan 22 '18 at 20:09

Antimony trioxide is a good example that's also relatively common in nature. If you still think antimony is too semimetallic, then various iodine oxides (e.g. IO$_2$) are solids at room temperature.

• Iodine is also a semi-metall – Anixx Jan 22 '18 at 20:07
• No it isn't. What's your definition of semimetal? It's not one I've ever seen before. – probably_someone Jan 22 '18 at 20:14
• Wikipedia plainly says iodine is metallic. – Anixx Jan 22 '18 at 20:31
• "Metallic" just means shiny in the context that Wikipedia is using. It does not mean that iodine is a metal. It's the same when you use "metallic" markers; it's a word used to describe their appearance, not material properties. – probably_someone Jan 22 '18 at 20:34

I think you are confusing metalloid with semimetal. These of course are squishy terms regardless and depend on what property you are looking at (physical or chemical behavior). But in general metalloid has more the connotation of small band gap semiconductor and semimetal the connotation of weak metal (small overlap of valence and conduction bands). So Si might be a metalloid but not a semimetal.

There are some weird halogen oxides that are liquids or unstable solids at near RT. Not sure if any meet your hurdle. And might need to be inside Pt or the like so as not to react with air or container.

Of course there are solid oxygen containing organic compounds that have only clear nonmetals in them. Maybe that is not an "oxide" though as they are molecular. (You could say the same of the halo-oxides I mentioned.)

Comment: I would prefer that this title be edited to include semimetal (or metalloid). It is annoying for the title to say something so different than the text of the question.