Crystal field spectra and jahn teller effect of Mn3+ in clinopyroxene and clinoamphiboles from India

Causes of the purple and pink colours of manganoan sugilites from the Wessels Mine, South Africa

“…These values are much higher than those normally reported for Mn 3+ in a distorted octahedral environment, which range from approximately 20 to 300 Ghose et al, 1986). However, a comparable value (1900) was found for Mn 3+ in purple yoderite, reportedly because of the five-fold coordination of the Mn-site and the covalency of the Mn3+-O bond .…”

Magnesio-arfvedsonite from Jade Mine Tract, Myanmar: mineral description and crystal chemistry

“…moving toward ferri-richterite) and that of Ghose et al (1986) If the C cations are distributed according to current knowledge of amphibole crystal-chemistry (for a review, see , we obtain, for the two magnesio-arfvedsonite specimens, the site populations reported in Table 6 together with the corresponding values of the site scattering (Sx i Z i ) and mean bond lengths (Sx i <cat i ÀO>), where Z is the atomic number and <catÀO> is the averaged cation-to-oxygen distance observed in amphiboles (for more detail, see Hawthorne et al, 1995;Hawthorne and Oberti, 2007;. The agreement between the refined and calculated site-scattering values is good; in contrast, that between the refined and calculated mean bond lengths show that the M(1) and the M(3) octahedra are slightly smaller than expected on the basis of composition.…”

“…A complete description of holotype magnesio-arfvedsonite AMNH H35024 from the Jade Mine Tract was approved by the IMA-CNMNC (IMA 2013-137, Oberti et al 2014. Mineralogical data and a comparison with the sample of Ghose et al (1986) are reported in this present paper.…”

The absorption- and luminescence spectra of Mn3+ in beryl and vesuvianite

“…(Abs- Wurmbach et al 1977;Ghose et al 1986;Sherman and Vergo 1988;Platonov et al 1995;Gaft et al 2011;Fridrichová et al 2017;Panikorovskii et al 2017) can indicate that for crystal sites with symmetry lower than axial and for which OH groups could also be ligands (Mn-monmorrillonite, amphibole, henritermierite, epidote and pink vesuvianite), the Dq parameter varies according to a known relationship D q ~ r (Mn-O, OH) −1 . The remaining crystals do not exhibit the same relationship.…”

“…The absorption spectra of Mn 3+ -bearing minerals have been measured for grossular (Gaft et al 2013), Mn-hydrogarnets (Hålenius 2004), Mnandalusite and kyanite (Abs-Wurmbach et al 1977;Hålenius 1978;Kai et al 1980;Smith et al 1982;Langer et al 1982;Abu-Eid et al 1978;Gaft et al 2011), yoderite , orthozoisite and clinozoisite (Langer et al 2002), rhodonite (Paião and Watanabe 2008), epidote Burns and Strens 1967), vesuvianite (Platonov et al 1995;Panikorovskii et al 2017), beryl Fridrichova et al 2017), diopside (Hålenius and Skogby 1996), clinopyroxene and amphiboles (Ghose et al 1986), montmorillonite (Sherman and Vergo 1988), chlorite (Hålenius 1984) and tourmaline (Smith 1978). The polarized-or un-polarized spectra measured for red-and purple crystals contain the main 5 E g → 5 T 2g transition band at 535-565 nm.…”