Why are they so rare? The challenge of obtaining rare earths lies not in their scarcity but in the complexity of mining and processing them.
"Light rare earths occur visibly in rock minerals
while medium and heavy rare earths exist in ionic form – like tea aroma absorbed in leaf veins – hidden within clay particles,
" said Wang Xueqiu
a scientist at China's Ministry of Natural
Resources.
"This invisible nature makes exploration extremely difficult."