Gabbro is usually made up of such as pyroxene, plagioclase, amphibole and olivine which makes it an intrusive igneous rock. It is not considered as a mineral since it is composed of an aggregate of minerals or non-minerals and does not have one specific chemical composition.
True, as an atom has the same chemical properties as the first bulk element. Dalton’s Atomic Theory explains all :))
This is an redox reaction, a combustion reaction.
For example:
4Al + 3O₂ = 2Al₂O₃
Al - 3e⁻ = Al⁺³
O₂ + 4e⁻ = 2O⁻²
