URL https://www2.city.kurashiki.okayama.jp/musnat/geology/mineral-rock-sirabekata/mineral44/epx-mineral/henkoukenbikyou-koumoku/henkoukenbi zougankoubutu/micro zougan photo/spinel32.jpg
URL2 https://www2.city.kurashiki.okayama.jp/musnat/geology/mineral-rock-sirabekata/mineral44/epx-mineral/henkoukenbikyou-koumoku/henkoukenbi zougankoubutu/micro spinel.htm
