cementation

The life of Tina Turner — her rise to stardom, her escape from an abusive relationship, her cementation as a figure of rock resilience — is revisited in this new documentary from Daniel Lindsay and T.J.

"We're most interested to find clues as to the aqueous geochemistry which resulted in cementation of the sedimentary rocks," he told the BBC this week.

In the cementation process, bars of wrought iron are imbedded in powdered charcoal in a fireclay trough, and kept at a high temperature in a furnace for several days.

Their hardness and the degree of cementation may be tested by means of a file.

He was familiar with amalgamation, cupellation, the separation of gold and silver by cementation with salt and by nitric acid.