If it is anodized aluminum, there are lots of posts regarding settings in the Beyond the Manual section of the forum. If it isn’t anodized aluminum, but is some other metal, it is unlikely that an attempt to engrave it would damage the Glowforge. That being said, wherever you purchased these should be able to provide an accurate material description.
Sooooo drumrollll its not magnetic. Now i have similar metal lighters that are red which are also not magnetic (i can engrave on these using mac pro settings).
Its just these smaller ones are far more shinier but as you can see in the image i scraped it a bit and you can see its coated. I did try mac pro settings and saw nothing so stopped the machine cause i didnt want to damage my machine.
As long as i cant destroy my machine in the process i will try again with new settings
The only thing you really have to worry about with damaging your machine while working metal is that copper is highly reflective on the laser’s spectrum so NOOO copper (unless 100% covered).
You will see discussions back and forth on any other shiny metals, but as you’re generally only using them when you’ve got something covering it (anodization, dry molly lube, paper towels, etc.) it’s less of an issue.