Antimony is a metal so they will call it an alloy. But there could also be a spectrum or clear demarcation between alloy and compound from a definition perspect

Antimony is a metal so they will call it an alloy. But there could also be a spectrum or clear demarcation between alloy and compound from a definition perspective, I don't know. I think it's cool this alloy actually looks like a crystal (ie, it's clear) rather than a metal. The only other metal thing I know that does that is ALON a transparent Aluminium ceramic, but there are probably lots. I think the difference between compounds, alloys, ceramics and glasses is maybe complex, but has something to do with the atomic lattice structure of the solid form. Ceramics and glasses will be less regular than compounds. Alloys I'm not sure!