磁鐵能量補充的磁石，附原盒28 x 18 mm，約 1750
Loadstone in its original case, 28 x 18 mm, circa 1750
A rare miniature silver-mounted loadstone, with decorated upper and lower frieze, silver suspension ring, magnet bar, contained in a black silk-lined fishskin-covered case with domed cover and single brass hook and eye.
A lodestone, or loadstone, is a naturally magnetized piece of the mineral magnetite. They are naturally-occurring magnets, which can attract iron. The property of magnetism was first discovered in antiquity through lodestones. Pieces of lodestone, suspended so they could turn, were the first magnetic compasses, and their importance to early navigation is indicated by the name lodestone, which in Middle English means 'course stone' or 'leading stone', from the now-obsolete meaning of lode as 'journey, way'.
Lodestone is one of only two minerals that is found naturally magnetized; the other, pyrrhotite, is only weakly magnetic. Magnetite is black or brownish-black, with a metallic luster, and has a Mohs hardness of 5.5–6.5 and a black streak.
錶殼 非常好, 少有使用過