Where does “камушек” come from?

камушек (Russian) comes from Russian ка́мень, from Old East Slavic камень, from Proto-Slavic kamy, from Proto-Indo-European h₂éḱmō, from Proto-Indo-European h₂eḱ- — sharp.

Ancestry of “камушек”, step by step

StepLanguageWordMeaning
1Russianка́меньstone, rock
2Old East Slavicкамень—
3Proto-Slavickamystone
4Proto-Indo-Europeanh₂éḱmōstone
5Proto-Indo-Europeanh₂eḱ-sharp
Every word from Proto-Indo-European h₂eḱ- →Every word from Proto-Indo-European h₂éḱmō →Every word from Proto-Slavic kamy →