Gibbsite:

• Chemical Name & Formula: Aluminium Hydroxide (or Tri-hydroxide), Al(OH)₃
• Technical or Common Name(s): Alumina Trihydrate (or simply ‘Trihydrate’ or ‘Hydrate’), usually written in oxide notation as Al₂O₃.3H₂O
• The most abundant economic source of alumina. It is also the intermediate product in the refining process.
• Requires the lowest refining temperature, typically 150^oC
  
  

Boehmite

• Chemical Name & Formula: Aluminium Hydroxy-oxide, AlOOH
• Technical or Common Name(s): Alumina Monohydrate, usually written in oxide notation as Al₂O₃.H₂O
• Requires higher refining temperatures, typically 240-260^oC
  
  

Diaspore

• Chemical Formula: AlOOH, but usually written in oxide notation as Al₂O₃.H₂O
• Has the same chemical composition as boehmite but a different crystal form. It does not occur in tropical bauxites but is of importance in Europe & China.
• Requires the highest refining temperatures to process, typically +260^oC

Source: World Bauxite Resources, USGS, CMGroup

India has 3,896 million tonnes of resources of bauxite which is sufficient to meet both domestic and export demands for metallurgical needs. However India is short of bauxite needed for refractories and chemical industries.

Reserves/Resources of bauxite in the country as on 1.4.2015, as per NMI database, based on UNFC system have been placed at 3,896 million tonnes. These resources include 656 million tonnes Reserves and 3,240 million tonnes Remaining Resources. By grades, about 77% resources are of Metallurgical grade. The resources of Refractory and Chemical grades are limited and together account for about 4%. By States, Odisha alone accounts for 51% of country’s resources of bauxite followed by Andhra Pradesh (16%), Gujarat (9%), Jharkhand (6%), Maharashtra (5%) and Madhya Pradesh & Chhattisgarh (4% each). (Source: IBM)

India exports bauxite to China, Saudi Arabia, France, Japan, Slovenia, USA, UK, Oman, Italy and Kuwait. China is the main importer of bauxites from India. Imports are quiet negligible in comparison to the exports; the ore is procured in lesser quantities from Guinea and Brazil, the two major suppliers of global bauxite. Currently the export duty on bauxite in 15%.