The Lamp / Lantern is one of the magical weapons, or elemental tools, of Western ceremonial magic, the set of implements the magician consecrates and uses in ritual. It stands for the higher self or divine light presiding over the four; it is not one of the four elemental tools but the fifth, quintessential principle.
Tool and element
Where the four elemental weapons answer to Fire, Water, Air and Earth, the Lamp answers to Spirit, the fifth element (quintessence) that crowns and unites them. The four elemental weapons, Wand, Cup, Sword and Pentacle, correspond to the four suits of the tarot's Minor Arcana and to the four points of the ritual circle, a scheme drawn together in the Hermetic Order of the Golden Dawn from 1888 out of older Solomonic and grimoire material.
The weapon is described here as an element of that documented tradition of ceremonial magic, a body of practice studied historically rather than endorsed.