The difference between them lies in different hardness, different luster and different categories.
Emerald belongs to beryl family and belongs to hexagonal system. Emerald crystals are usually hexagonal columns with few vertebral surfaces. There are pits on the cylindrical surface and the bottom axial surface. Almost all emeralds are broken in appearance, with many inclusions and extremely rare crystals, because they are generated in rock strata that are often squeezed by stress.
Emeralds have different chemical compositions. Emerald is jade, not rock. Emerald is a gem or mineral. Emerald is a mineral crystal of aluminosilicate, but it looks green because it contains chromium, a trace element. Jadeite is a polycrystalline aggregate, which is mainly composed of jadeite, omphacite and sodalite.
The correct definition of jadeite with different properties is fibrous aggregate composed of pyroxene minerals mainly composed of jadeite minerals. Emerald is known as the king of emeralds, as rare as the bright red Ulan Nu, and it is one of the four precious gems (red, blue, emerald and diamond) recognized by the international jewelry industry.
Emerald and jade are completely different things. Simply put, emeralds are "emeralds" and jadeites are "jade".