A natural curiosity seems to have been caused by the mineral properties of the local spring water. They became known as ’Harrogate Diamonds’. The first mention we have of them is in Dr Thomas Short’s ’History of Mineral Waters’ published in 1734. He says of the Chalybeate waters:

"….about 200 yards south-east of the Bogg, when the ground is new plow’d, or harrow’d, and has a shower of rain, follow’d with a bright sunbeam, there are found beautiful, small. Hard, transparent stones called diamonds."

Although these crystals were not actually diamonds, some were hard enough to cut glass.