Sulfur (S)
Origin location = Unknown, but is commercially pure and very yellow.
Image created with B&L SZ5 microscope @ 10x, coupled to a ccd camera and computer at 10x.
Intense lighting takes away from the minor amount of yellow sublimates surrounding the meted sulfur as the heat melted this pinch of powdered sulfur.
Colors are accurate.
Why the grayish and orange-reddish pink colors formed I don’t know, but is likely due to heating (burning), which was not intensive.
Although a cavity was gouged into the plaster tablet this powder moved when only a little blast from torch was applied, but because it melted quickly it stuck just outside the depression cut into plaster tablet.