hello - it's very attractive, nice find, and amethyst is always a winner in terms of colour.
The word intaglio has become a little over used, and probably mis-used, during the C19 and C20, but it does cover cutting or engraving below the surface, and leaving a pattern or design which appears as in relief - I think we all know what someone means now if they use the word, even if this is not quite what it meant in the C17. Your piece looks to be wheel cut rather than wheel engraved.
I'm not aware that a 22 point star signifies anything in particular - period stars were usually 16, 24 and 32 points - but the cutting of the centre of the star does indicate quality, or otherwise. A lack of neatness at the intersection indicates poor quality often.
This looks to be thinly cased rather than stained or flashed, and I'd have thought somewhere in the first half of the C20, possibly.
Regret I can't help with origin - this sort of product was made in most countries, but your suggestion of Bohemia might be nearer the mark, as a generalization.
Looks a bit big for a powder pot, but I'd agree it does have the appearance of something from a woman's dressing table.
Sorry this is of no help, fingers crossed someone else will have better information.