Several years ago, we answered the question What’s So Rare About Rare Earth Elements? As we noted, although originally thought to be rare, many of the Rare Earth Element (REE) minerals are actually common in the Earth’s crust. However, these elements rarely exist in pure form; they are usually found within other minerals, making them difficult to extract from the ore and costly to mine.
According to the USGS Rare Earths Report, the principal economic sources of rare earths are the minerals bastnasite, monazite, and loparite and the lateritic ion-adsorption clays. The elements range in crustal abundance from cerium, the 25th most abundant element of the 78 common elements in the Earth’s crust at 60 parts per million, to thulium and lutetium, the least abundant rare-earth elements at about 0.5 part per million.
Rainbow Rare Earths Ltd (LON:RBW) is a mining company focussed on production from, and expansion of, the high grade Gakara Rare Earth Project in Burundi, East Africa. With in-situ grades in the range of 47-67% Total Rare Earth Oxide (TREO), Gakara is one of the world’s richest rare earth deposits.