Definition of blue ground in English:

blue ground

noun

  • another term for kimberlite
    • ‘To the northwest in section 8, a group of grassy springs with some 'blue ground' were found.’
    • ‘In the early days, blue ground was dumped in big piles and the miners waited to extract the diamonds until weathering had turned the kimberlite into yellow ground.’
    • ‘When they reached the bottom of the soft yellow ground and struck the "blue ground" that lay underneath, many miners thought their claims had petered out.’