I have found a number of welsh bricks in Thatto Heath and Ravenhead but having photographed an Adamantine brick was something else and special. This partial half bat was hidden among undergrowth and had to require a little cleaning. Did a little research on this unusual brick as it was made in Buckley Chester but has the brick mark of "Made in England" The brick maker was Charles Davidson and son and the firm was indeed from Buckley Flintshire. Some information I have read said that the brick mark was a marketing ploy.
Adamantine means: very hard or unbreakable.
The brick has been left in its original finding place for others to find.