Definition of kidney ore in English:

kidney ore

noun

  • [mass noun] Haematite occurring in rounded, kidney-shaped masses.

    • ‘Hematite specimens occurring as ‘kidney ore’ were found to some degree in most of the area's mines.’
    • ‘Typically the Furness haematite is found in rounded masses, resembling animal kidneys, and so is known as kidney ore.’
    • ‘It produced a large number of fine specimens of grape ore and kidney ore.’