↑   Estimates range throughout the world, but most resources give a determine of two–4kg of bauxite for every 1kg of alumina. Bauxite, a major aluminium ore. The purple-brown colour is because of the presence of iron oxide minerals. Over-all, the Earth is about 1.59% aluminium by mass (seventh in abundance by https://fire-rated-ductwork-induc91234.livebloggs.com/43864474/5-essential-elements-for-aluminium-greenhouse