Flint is a dense, hard and resilient rock. The raw and blue flint was originally formed in cavities of lime formations on the seabed more than 60 million years ago.
The raw flint is delivered from a gravel pit nearby and sorted before being transported to the kilns.
When the flint is calcined to approx. 1150°C the water is liberated and the flintstone becomes white and crystalline in character. After 2-4 days the white flint is removed from the bottom of the kilns.
After calcination the white flint is crushed and sieved into the required fractions.