Pulhamite

Pulhamite was a patented anthropic rock material invented by James Pulham (1820–1898) of the firm James Pulham and Son of Broxbourne in Hertfordshire.

It was widely used for rock gardens and grottos.

Pulhamite, which usually looked like gritty sandstone, was used to join natural rocks together or crafted to simulate natural stone features.

It was so realistic that it fooled some geologists of the era.

[2] Modern analysis of surviving original Pulhamite have shown it to be a blend of sand, Portland cement and clinker sculpted over a core of rubble and crushed bricks.