Show RADIUM NEVER SEEN IN NATURE radium is a metal and is described at having a white metallic luster it has be bee isolated only once or twice and few pi pie have seen it radium is ordinarily w 0 bained from its ores in the form of hadr sulphate chloride or bromide and it is ill the form of these salts that it is asua usua usually I 1 sold and used these are all white 0 01 nearly white substances whose app appearance earan is no more remarkable than common sai sal i or baking powder radium is found in D na a ture in such exceedingly small quan titie that it is never visible even when the M ma aerial is examined with a microscope 0 or dina rily radium ore carries only a sma smal fraction of a grain per ton of material an am radium will never be found in large quant ity because it is formed by the decay 0 uranium a process which is wonder wonderfully full slow and radium itself decays and changes change i to other elements so rapidly that it is i biffl possible for it to accumulate naturally i visible masses minerals that carry radium however are fairly easy to determine of them pitchblende as generally found is a black mineral about as heavy as ardi nary iron but much softer the principal radium mineral has a brighh canary yellow color and is generally po dery there are other radium bearing inin brals of less importance |