Paratooite-(La)

{{infobox mineral

| name = Paratooite-(La)

| category = Carbonate mineral

| image = Paratooite-(La)-132875.jpg

| imagesize = 260

| alt =

| caption = Paratooite-(La): Locality: Paratoo copper mine, Yunta, Olary Province, South Australia, Australia. Field of view 6 mm.

| formula = (La,Sr,Ca)₄CuCa(Na,Ca)₂(CO₃)₈

| IMAsymbol = Pto-La{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3 |pages=291–320|doi=10.1180/mgm.2021.43 |bibcode=2021MinM...85..291W |s2cid=235729616 |doi-access=free}}

| strunz = 5/B.0; 5.AD.20 (Nickel-Strunz)

| dana =

| system = Orthorhombic

| class = Dipyramidal: mmm

| symmetry = Pbam

| unit cell = a = 7.2250, b = 12.7626 c = 10.0559 [Å]

| color = pale turquoise-blue to pale blue

| habit = blades (sheaves) intergrown to form spray-like aggregates

| twinning =

| cleavage = {100} (possible)

| fracture =

| tenacity =

| mohs = 4 (probably)

| luster = vitreous or pearly

| streak = pale blue

| diaphaneity =

| gravity = 1.97-2.02 (measured)

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| polish =

| opticalprop = biaxial negative, α = 1.605(3), β = 1.696(3), γ = 1.752(2)

| refractive =

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| pleochroism = moderate, very pale blue (X) to greenish blue (Y = Z)

| 2V = 72.6 °

| dispersion =

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| melt =

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| references = Pring, A., Wallwork, K., Brugger, J., Kolitsch, U. (2006) Paratooite-(La), a new lanthanum-dominant rare-earth copper carbonate from Paratoo, South Australia. Mineralogical Magazine, 70, 131-138Mindat, Paratooite-(La), https://www.mindat.org/min-27579.htmlHandbook of Mineralogy, Paratooite-(La), http://www.handbookofmineralogy.org/pdfs/paratooite-(La).pdf

}}

Paratooite-(La) is a complex lanthanum copper(II) calcium sodium carbonate mineral, representing a unique elemental combination among the known minerals. It is a secondary, weathering mineral.Pring, A., Wallwork, K., Brugger, J., Kolitsch, U. (2006) Paratooite-(La), a new lanthanum-dominant rare-earth copper carbonate from Paratoo, South Australia. Mineralogical Magazine, 70, 131-138Mindat, Paratooite-(La), https://www.mindat.org/min-27579.htmlHandbook of Mineralogy, Paratooite-(La), http://www.handbookofmineralogy.org/pdfs/paratooite-(La).pdf There is a heterovalent diadochy substitution of lanthanum by strontium and calcium; also sodium is substituted by calcium in the mineral. Its structure proved to be more difficult to describe within the initial approach. It was later shown to be a superstructure of another rare earth carbonate mineral, carbocernaite.Krivovichev, S.V., Panikorovskii, T.L., Zolotarev, A.A., Bocharov, V.N., Kasatkin, A.V., Škoda, R. (2019) Jahn-Teller distortion and cation ordering: The crystal structure of paratooite-(La), a superstructure of carbocernaite. Minerals, 9, 370 The "-(La)" suffix in the mineral's name is known as Levinson suffix. It refers to the particular element, of a group of elements (notably lanthanides), that dominates in the particular structural site. As such, the element would show major, dominant occupancy at this particular site.Burke, E.A.J., Kampf, A. (2008) The use of suffixes is mineral names. Mineral Matters, in: Elements, 96; http://elementsmagazine.org/archives/e4_2/e4_2_dep_mineralmatters.pdf, visited 21.12.2019