Engraved this Black Granite stone on my D1 Pro 20w. It took approximately 2 hrs and 20 mins of laser time. I did this to gift to my mother, as we lost my grandma earlier this year, and my grandfather back in 2017. Both of my grandparents were cremated, and I wanted to gift my mother a piece to memorialize them (since they don't have a gravesite with a headstone.) No prep work on the granite stone, other than cleaning it to remove any surface debris/fingerprints/etc.

Lightburn settings: 6000 mm/min @ 75% power, constant power - ON, Line Interval - .08 mm, 2 passes