Gottardiite, a new high-silica zeolite from Antarctica

• Published in: European Journal of Mineralogy
• Main Authors: GALLI E., QUARTIERI S., VEZZALINI G., ALBERTI, Alberto
• Other Authors: Galli, E., Quartieri, S., Vezzalini, G., Alberti, Alberto
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1996
• Subjects: Antarctica; Chemical and physical propertie; Gottardiite; Powder diffraction; Zeolite; Victoria Land; Adamson; Antarc*
• Online Access: https://hdl.handle.net/11392/1204280; https://doi.org/10.1127/ejm/8/4/0687; https://www.schweizerbart.de/papers/ejm/detail/8/83483/Gottardiite_a_new_high_silica_zeolite_from_Antarct?af=crossref

Gottardiite has been discovered in the Jurassic Ferrar dolentes of Mt. Adamson (Northern Victoria Land, Antarctica). The new zeolite occurs as subparallel aggregates of transparent pseudo-hexagonal lamellae. The mineral is orthorhombic, space group Cmca, with a = 13.698(2), b = 25.213(3) and c = 22.660(2) Å The strongest X-ray diffraction lines are (in Å): 11.34(100), 4.37(79), 4.01(57), 3.282(68). The gottardiite framework topology is the same as that of synthetic NU-87. The chemical formula is: Na2.5K0.2Mg3.1Ca4.8 Al18.8Si117.2O272·93H2O. TheSi/Al ratio is 6.2, the highest found up to now in a natural zeolite. Gottardiite is optically biaxial (-), with α = 1.480(2), β = 1.485(2), γ = 1.486(2), 2V < 60°, where X = b, Y = a and Z = c. The density is 2.14(4)g/cm3 (obs.), and 2.16g/cm3 (calc.). Both thermal stability and rehydration capacity are very high. The name is in honour of Glauco Gottardi (1928-1988).