The acid used to etch the surface has darkened the parts richest in copper, while those richest in tin remained white.
Etch designs in the pot and set aside to dry.
There are a few materials you'll need to etch on glass both successfully and safely.
However, it can stain and etch if not cared for properly.
But if we polish the solid alloys, etch them if necessary, and examine them microscopically, we shall find that alloys on the lead side of the diagram consist of comparatively large crystals of lead embedded in a minute complex, which is due to the simultaneous crystallization of the two metals during the solidification at the eutectic temperature.