Wait what? Now I'm confused. I thought you were arguing that a solid ruby worth X was still worth X when crushed into dust? But the above post seems to contradict that completely. To make sure I'm understanding you correctly, could you please clarify your answers to the following questions?
If a player in your game finds in a treausre a cut ruby worth 500 gp, and crushes it, how much is the resulting dust worth?
If a player in your game finds in a treasure a rough, uncut ruby worth 500 gp, and crushes it, how much is the resulting dust worth?
If a player in your game finds in a treasure a rough, uncut ruby worth 500 gp, uses gemcutter's tools to cut it into a 1000 gp cut ruby, and crushes it, how much is the resulting dust worth?
I had thought your answers would be 500/500/1000, but maybe I misunderstood? (For reference, my answers are "a whole lot less than 500"/"more, but still a whole lot less than 500"/"identical to the previous, assuming the player kept the trimmings.")