What was one of the hardest stones known to man that the Olmec carved masks?

One of the hardest stones known to man that the Olmec carved masks from is jadeite. This highly durable and lustrous material was prized for its beauty and significance, often associated with status and power in Olmec culture. The Olmec's ability to carve intricate designs from jadeite demonstrates their advanced craftsmanship and symbolic artistry.