2.Laterite-type bauxite (plateau or silica bauxite)
2.Concealed bauxite deposits
1.Stratified bauxite within sedimentary series and coastal-plain bauxites H)
2.Colluvial bauxite (redeposited)
The name bauxite originated from theLe Baux deposit, France, and is used forrocks made up of gibbsite, boehmite, diaspore and phyllosilcates, mainly kaolinite and minor smectite. Subordinate amounts of silica, Fe oxide hydroxides and Ti oxides mayalso occur in the rock.
Bauxite developed underhumid tropical climatic conditions (allitic chemical weathering). All kinds igneous, sedimentary and metamorphic rocks containing Al may produce bauxite; the most favourable parentrocks are nepheline syenites, shales, gneisses enriched in feldspar and graywackes
Bauxite classification schemes are based on geomorpholoy, bedrock lithology, mineralogical composition and shape of deposit
Bauxite specification (mineralogical)
Trihydratic bauxite(35 % H2Ocrist): gibbsite > boehmite or diaspore (easy to grind)
Monohydratic bauxite (15 % H2Ocrist): boehmite or diaspore > gibbsite (hard to grind)
Michael's answer is quite intriguing because aluminium-bearing minerals are rare in ultramafic rocks and as such, accumulating a substantial amount of Al to form an ore is rare even in the most extreme of weathering.
The Nkamouna cobaltiferous Nickel laterite deposit in southeastern Cameroon contains substantial gibbsite. However, the gibbsite was precipitated from Al leached from the overlying highly weathered schist and not sourced from the serpentinite ultramafic protolith.