Boracite - Boulby Mine, N.Yorkshire

Boracite - Boulby Potash Mine, Loftus, Redcar and Cleveland,  North Yorkshire
T/N : 25 x 17 x 10mm
Hilgardite  Ca2B5O9Cl·H2O , Boracite  Mg3(B7O13)Cl  
 
Excellent thumbnail example of this rare Borate mineral with superb micro crystals  from the important find of the early 1990s of aqua blue- green coloured Boracite and associations of Hilgardite crystals of a slight salmon pink.
Material is increasingly difficult to get now from that one find.
 
The Boulby Mine is one of Britains deepest mines, extracting potash (Potassium) and salt from the evaporate deposits of the Zechstein Formation.
 
https://www.mindat.org/min-1902.html