Hi Dave, hope your holiday was good.
Thanks for the detail on the silca stones. Looking at my earlier comment again, I am now wondering if I have mixed up some things I was told a few years back. Not sure if I can even find any notes to make sense of it.
Anyway, given that the Strathearn company was a renaming of Vasart Ltd by Teachers, following the move to the new factory at Crieff, I should have thought about my info before posting.
Assuming quartz was not used in any Vasart Ltd weights, it makes little sense to suggest that it was gathered from the Tay! I just wish I could recall who told me about this and when.
Sorry to all readers for my use of unchecked information earlier.