Gabriel, welcome to the board. You've raised an interesting topic with the Lynn question. I think we may need to split off the Lynn sand posts into a separate topic for future reference.

I also had a poke around to see what I could find, and came across a book titled
A Dictionary of Art, Manufactures, and Mines, by Andrew Ure, M.D., (published by D. Appleton & Company, 1856) in which is stated a little about the sand from Lynn. Here is the link to the :
BOOK. The whole section on Glass and Glassmaking is fascinating, it starts at page 899 and ends on page 932.
There is also a snippet in
Treatise on the Art of Glass Making ... To which is added, a treatise on the alkalis, oxides, silex, &c., used in the mixing and colouring of glass, etc by William GILLINDER (published W. Gillinder, 1851), where he explains the difference between Lynn sand and Alum Bay sand and how to test it!
BOOK