1) Hexagonal mineral 
Feroxyhyte is an oxide/hydroxide of iron, δ-Fe3+O(OH). Feroxyhyte crystallizes in the hexagonal system. It forms as brown rounded to concretionary masses. Feroxyhyte is opaque, magnetic, has a yellow streak, and has a relative density of 4.2. It occurs in manganese-iron nodules on the Atlantic and Pacific Ocean floors. It is also found in the Bal...