rhenium: a rare heavy polyvalent metallic element that resembles manganese chemically and is used in some alloys; is obtained as a by-product in refining molybdenum
matter: that which has mass and occupies space
manila tamarind: common thorny tropical American tree having terminal racemes of yellow flowers followed by sickle-shaped or circinate edible pods and yielding good timber and a yellow dye and mucilaginous gum