Earth's core is made mostly of

A. silicon and oxygen.
B. iron and nickel.
C. silicon and magnesium.
D. iron and magnesium.

iron and nickel

Explanation:

Deep inside the Earth's core, near the center is iron and nickel.

for points guys

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).