hi Timbuk
here is pics of my friend agates.
we think as it seems your piece is a early 20 century etched carnelion. and that has been belong to shiea people from gujerat.we can see word shahid and hussein.it is normal for shiea people to use these words like.ya hussein shahid.hussein grandson of prophet and shahid means martyred.
if we were able to see it from close it was easier to say.
cheers
Ali