A trace radioactive element, symbol, Ra. It occurs in uranium ores
A trace radioactive element, symbol, Ra. It occurs in uranium ores
Marine protozoa subject to silica replacement fossilization sound in limestone, shale and other rocks
Lines converging at a single center
Alpha, beta or gamma energy emitted by the decay of atomic nuclei from their radioactive source
Having the shape of a kidney
Another term for the shape of the earth surface at a specific point
The layer of rocks, gravel, sand, soil and other matter between surface and bedrock
Ore whose minerals resist separation by initial chemical processes and require further chemical decomposition
The percentage of valuable minerals successfully recovered in ore
An initial exploration and ground survey of mineral lands