The clay from Armadale's mines was of such quality, it made fireclay bricks, and was used where industrial-strength bricks were required, such as in kilns.
In addition, ceramic pipes, chimney pots and sanitary-ware was manufactured.
You can read more information in armadale.org.uk here
Here Kenny Smolak describes his experiences working at Etna Brickworks;
First Job in Brickworks
Pay and Bonuses
Work times and Breaks, travelling to the Brickworks
How did he get the job?
How long did he work there each Summer?
What was the first day like? What were the bosses like? What Practical Jokes were played?