Chromium Nitrate Nanoparticles nanodots or Nanopowder are black spherical high surface area metal particles. Nanoscale Chromium Particles are typically 10-30 nanometers (nm) with specific surface area (SSA) in the 30- 70 m2/g range and also available with an average particle size of 70-100 nm range with a specific surface area of approximately 5- 10 m2/g.