He didn’t laser engrave those, they are stamped.
Here’s another possibility you could try on your Glowforge.
These were made by doing a deep engrave on Baltic birch. Then flooded a little UV resin into the engrave, then applied four coats of silver embossing powder. Afterward, it’s pretty easy to scrape the excess embossing powder from the cavity (soften it by painting with a bit of alcohol first).
I’m not sure they would hold up well for jewelry though. Maybe if you coated the whole thing with resin.
yes it is my go to and the least messy.