No data presented in article cited. Mineral identified to the series level, only. Paragenesis indicates late-stage crystallization and unlikely to be amblygonite with F>OH.
Quality of samples:
not specified / average specimens
Confirmation
Validity:
Unconfirmed/Questioned
References
References:
Switzer (1938) The Paragenesis of the Center Strafford, New Hampshire Pegmatite. American Mineralogist 23:811