malmiest

/ˈmɑlmiɪst/
adjective
  1. Superlative form of malmy: containing the most malm, or having the most soft, crumbly quality of malm rock.
    • The malmiest layer of the quarry is at the bottom, where the rock is most powdery.
    • Of all the local stone, this is the malmiest and least suitable for carving.
    • Gardeners seek out the malmiest soil for their root vegetables.