41. The mine has attracted increased attention in recent years as rare earth elements had become increasingly in short supply. 42. Depletion or enrichment of europium in minerals relative to other rare earth elements is known as the europium anomaly. 43. The IIG said it did not find data supporting the presence of rhenium or any other rare earth element . 44. All the other rare earth elements are present in subordinate amount, and tantalum substitutes for some of the niobium. 45. The exact number of rare earth elements that existed was highly unclear, and a maximum number of 25 was estimated. 46. These rare earth element patterns are similar to the Late Miocene Maricunga Belt rocks and contrast to early Miocene rocks. 47. Element substitution for the calcium cation often includes certain rare earth elements ( REE ), such as yttrium and cerium. 48. Using the Thomas Fermi model, she predicted that they would form a new series similar to the rare earth elements . 49. Evidence favour of an intact Pleistocene deposit comes from analysis of rare earth elements ( REE ) in the megafauna bones. 50. The small town of Molycorp Minerals is a recently reactivated rare earth element mine on the southern flank of the mountain.
