Where does “*albastrum” come from?

*albastrum (Vulgar Latin) comes from Latin Albus, from Proto-Italic alβos, from Proto-Indo-European h₂élbʰos — white.

Ancestry of “*albastrum”, step by step

StepLanguageWordMeaning
1LatinAlbuswhite properly without, dull white
2Proto-Italicalβoswhite
3Proto-Indo-Europeanh₂élbʰoswhite

Words derived from “*albastrum

Every word from Proto-Indo-European h₂élbʰosEvery word from Proto-Italic alβosEvery word from Latin Albus