The name apatite refers to a subgroup of endmembers inside of a group, which are all included in an apatite supergroup. Apatite popularly refers to Ca5(PO4)3(F,Cl,OH), but there are over 40 known species of this mineral.
This widespread mineral can be found in human bones, comets, and all over the Earth in sedimentary, igneous, metamorphic, and hydrothermal rocks. It is the most abundant source of phosphorus and is involved in numerous industrial and scientific advancements.
The diverse characteristics found in the apatite supergroup are due to its “robust” atomic structure. Robust, in a system, can be defined as the ability to withstand or…show more content…
Metasomatism is when an aqueous solution chemically alters a rock that in encounters. Apatite is a useful tool for identifying these metasomatic changes in rocks. This widespread mineral, being a reservoir, can give information on timing, duration, and composition of this solution. The two main factors involved in tracking metasomatic processes in apatite are apatite’s anion column and the presence or absence of rare earth elements. Apatite’s anion column is important because the elements and/or compounds found there can substitute for each other in copious amounts, if not completely. You can use knowledge of what the composition of apatite in a rock typically should be to determine what change a varying apatite has undergone. For example, apatites found in a volcanic field might have a high percentage of F and much lower percentages of Cl and CO3. If apatite is found in the same or similar areas with a composition much different than that, say elevated levels of Cl and CO3 but low levels of F, then you could infer that an aqueous solution rich in Cl and CO3 has passed through and reacted with the apatite. Rare earth elements (REEs) indicate metasomatism in a comparable way. While the anion column shows changes through composition, REEs communicate change with inclusions, specifically, the presence of the minerals monazite and xenotime. “The formation and growth of monazite and xenotime as inclusions are the results of coupled