Liddicoatite from
Anjanabonoina pegmatites, Ambohimanambola, Betafo District, Vakinankaratra, Madagascar
| Locality type: | Pegmatite Field | |
| Classification | ||
|---|---|---|
| Species: | Liddicoatite | |
| Formula: | Ca(Li2Al)Al6(Si6O18)(BO3)3(OH)3(OH) | |
| Comments: | Liddicoatite was described as a new species in the tourmaline group by Dunn et al. (1997). The type locality was given as "near Antsirabe". One of the most likely localities, but not conclusively, would be Anjanabonoina. Thus multicolored tourmalines from Anjanabonoina was labeled as liddicoatite by dealers and collectors. In 2011 the holotype of "liddicoatite" was redefined as fluor-liddicoatite. F-dominant tourmalines (fluor-liddicoatite) is verified from Anjanabonoina, but (probably)not -yet- a (OH)-dominant (= liddicoatite after the new redefinition). A gem-quality purplish-red tourmaline sample of alleged liddicoatitic composition turned out to be elbaite in composition (Bosi et al. 2021). The polychromatic tourmalines from Madagascar show a very complex chemistry, and the different color zones in a single crystal may also represent different tourmaline species. Only single crystal x ray diffraction combined with a wavelength dispersive spectrum from an electron microprobe of a tourmaline is necessary to establish if fluor-liddicoatite (F- dominant on the W –site) or liddicoatite (OH-dominant on the W-site), elbaite, or other species is present. | |
| Confirmation | ||
| Validity: | Unconfirmed/Questioned | |
| Data | ||
| Mineral Data: | Click here to view Liddicoatite data | |
| Locality Data: | Click here to view Anjanabonoina pegmatites, Ambohimanambola, Betafo District, Vakinankaratra, Madagascar | |
| Data Identifiers | ||
| Mindat Occurrence Record ID: | 44546 | |
| Long-form Identifier: | 1:3:44546:1 | |
| GUID (UUID V4): | 0 | |
| Nearest other occurrences of Liddicoatite | ||
| 44.6km (27.7 miles) | ⓘAmbatonapetraka pegmatites, Mangarano, Antsirabe II District, Vakinankaratra, Madagascar | |
| 44.9km (27.9 miles) | ⓘAntsofimbato pegmatites, Mangarano, Antsirabe II District, Vakinankaratra, Madagascar | |
| 47.1km (29.2 miles) | ⓘTsarafara Sud (Ankadilava), Tsarafara Pegmatites, Sahatany Valley, Ibity, Antsirabe II District, Vakinankaratra, Madagascar | |
| 57.8km (35.9 miles) | ⓘTsilaizina pegmatite, Sahanivotry Manandona, Antsirabe II District, Vakinankaratra, Madagascar | |
| 62.6km (38.9 miles) | ⓘAntandrokomby pegmatite, Manandona Valley, Sahatsiho Ambohimanjaka, Ambositra District, Amoron'i Mania, Madagascar | |
| References | ||
Dirlam, Dona M., Laurs, Brendan M., Pezzotta, Federico, Simmons, William B. (Skip) (2002) Liddicoatite Tourmaline From Anjanabonoina, Madagascar. Gems & Gemology, 38 (1) 28-53 doi:10.5741/gems.38.1.28 | ||
