Noun
the outer layer of the Earth
Source: WordNetBiological effects Due to their sparse distribution in the earth's crust and low aqueous solubility, the lanthanides have a low availability in the biosphere, and are not known to naturally form part of any biological molecules. Source: Internet
Potassium makes up about 2.6% of the weight of the earth's crust and is the seventh most abundant element in the crust. Source: Internet
The earth's crust contains less than 1 part per billion of polonium, making it one of the ten rarest metals on earth. Source: Internet
There are only 5 parts per billion of tellurium in the earth's crust and 15 parts per billion of tellurium in seawater. Source: Internet
In addition, the picroilmenites show little resorption conducive for the preservation of higher quality diamonds surviving their transport from the mantle to surface of the Earth's crust.' Source: Internet