Properties of Gravitationally Bound Dark Compact Ultra Dense Objects
  We consider compact astrophysical objects formed from dark matter fermions of mass 250 GeV to 100 TeV or from massless fermions hidden by vacuum structure of similar energy scale. These macroscopic objects have maximum stable masses of sub-planetary scale (asteroids) and radii of micron to centimeter scale. We describe the surface gravity and tidal forces near these compact ultra dense objects, as pertinent to signatures of their collisions with visible matter objects. 
Christopher Dietl, Lance Labun, and Johann Rafelski
astro-ph.CO hep-ph