Carclaze is a suburb of the town of St Austell in mid-Cornwall, England, United Kingdom. The suburb forms part of the civil parish of Treverbyn and gives its name to the china clay works to the north.Carclaze mine produced tin and china clay for over 400 years. The tin ore is intermixed with shorl and quartz and is quarried rather than mined, with the whole rock crushed and washed to separate the tin.