Canadian Mineralogist Vol. 18, pp. 25-29 (1980) SABINAITE, A NEW ANHYDROUS ZIRCONIUM-BEARING CARBONATE MINERAL FROM MONTREAL ISLAND, QUEBEC J.L. JAMBOR CANMET, 55S Booth Street, Ottawa, Ontario K1A 0G1 B.D. STURMAN Department of Mineralogy and Geology, Royal Ontario Museum, Toronto, Ontario M5S 2C6 G.C. WEATHERLY Department of Metallurgy and Materials Science, University of Toronto, Toronto, Ontario M5S 1A4 Abstract rant au maximum 0.01 x 0.001 mm. Biaxe negative, IV 85°. a 1.74(2), P 1.80(2), v 1.85(1), X presque Fine-grained, white, powdery coatings and chalky perpendiculaire aux plaquettcs. L'analyse donnc aggregates of sabinaite occur in vugs in a dawsonite- Na.O 20.7, CaO 0.2, ZrO, 39.1, HfO, 0.47, TiO, rich silicocarbonatite sill at Montreal Island, Que 12.0, CO, 27.1, total 99.57 (poids). La sabinaite bec. The mineral is platy. roughly pseudohexagonal, est anhydre; sa teneur en fluor est ndgligeable; with maximum dimensions 0.01 x 0.001 mm, biaxial sa formule est (Na,Ca)».M(Zr,Hf)4.,0Ti,.MO».Ti> negative with IV 85°, a 1.74(2). P 1.80(2). r (CO,)„.,n soit, idealemenl. Na„Zr,+,Ti,09(CO,)„ x 1.85(1), X nearly normal to the plates. Analyses = 0.25. Elle ne reagit pas avec les acides froids, gave Na.O 20.7, CaO 0.2. ZrO, 39.1. HfO, 0.47. mais est soluble avec effervescence dans HCI chaud. TiO, 12.0, CO, 27.1, total 99.57 wt. %. Sabinaite La sabinaite est monoclinique; les dimensions de is anhydrous and has low or negligible F. The la mnille, obtenues en partie par diffraction elec- analytical formula is (Na,Ca)R.M(Zr,Hf)4.j»Ti,.M troniquc et en partie aux rayons X sur cliche 0,.,„(CO.,),.,o, theoretically NasZr^TiA^COa),, de poudre. sont: a 6.605(3), b 10.186(5). c 37.94 where x — 0.25. The mineral is unreactive in cold (5) A, P ~ 90". D„lc = 3.41 pour Z = 8 (for acids but is soluble with effervescence in warm mule analytique), Dm. 3.36. Les cinq raies les HCI. Sabinaite is monoclinic; cell dimensions, ob plus intenses du cliche' de poudre sont: 8.97(10) tained partly by electron diffraction and partly (012). 2.991(6)(036), 2.017(5)(240), 1.847(6), from the powder X-ray pattern, are a 6.605(3), 1.646(5). Le spectre infrarouge confirmc la pre b 10.186(5), c 37.94(5) A, P ~ 90°. D„„ is 3.41 sence de carbonate et l'absence de H,0 et d'OH. g/cms for Z = 8 (analytical formula), whereas Par ATD et ATG, on obtient une perte de poids £)„„ is 3.36 g/crn". Strongest lines of the powder de 28.1% et surtout du ZrO, monoclinique commc pattern are 8.97(10)(012), 2.991(6)(036), 2.017 produit de decomposition. La nouvelle espece est (5X240). 1.847(6). 1.646(5). The infrared spec dcdiee a Ann Phyllis Sabina, de la Commission trum of sabinaite confirms the presence of car gcologique du Canada. bonate and the absence of H,0 and OH. DTA and (Traduit par la Redaction) TGA gave a weight loss of 28.1%. with decom position mainly to monoclinic ZrO,. Sabinaite is Mots-cits: sabinaite, silicocarbonatite, carrierc St- named in honor of Ann Phyllis Sabina, of the Michcl, Montreal, dawsonite, carbonate anhydre de Geological Survey of Canada. zirconium et de titanium. Keywords: sabinaite, silicocarbonatite, St-Michel quarry, Montreal, dawsonite, anhydrous carbonate Introduction of zirconium and titanium. Dawsonite-bearing silicocarbonatite sills ex Sommaire posed in a limestone quarry at St-Michel, Mont real Island, Quebec, contain a varied mineralogy On trouve la sabinaite en enduits blancs, fine- ments grenus, pulvcrulcnts et en agrlgats crayeux that includes several unique barium- and zir dans les vacuoles d'un sill de silicocarbonatite a conium-bearing carbonates and a few as-yet- dawsonite sur l'ile de Montreal (Quebec). Elle unidentified minerals (Sabina 1979). In 1967 se prcsente en plaquettcs pseudo-hexagonales mesu- a new Na-Zr-Ti mineral was recognized and 25 Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/18/1/25/4005447/25_18_1_cm.pdf by guest on 29 September 2021 26 THE CANADIAN MINERALOGIST subsequently designated as mineral No. 5 (Sabi Compact aggregates have a vitreous lustre, but na 1976, 1979) For almost a decade only a in some cases flakes are aligned and impart a minute amount of this mineral was available, silky lustre to thin coatings. The hardness of but persistent collecting and X-ray identifi the mineral could not be determined. cations by A.P. Sabina eventually resulted in Optical and scanning electron microscopy of the acquisition of sufficient material for a sabinaite shows that it is platy and commonly chemical analysis and characterization. The new roughly pseudohexagonal. Grains are generally mineral is named sabinaite in honor of Ann equant, but most of the prism edges are ir Phyllis Stenson (n6e Sabina), whose initial work regular. A few grains are well formed (Fig. 1) led to the recognition of the unusual mineral and have crystal edges that intersect at 115 to assemblage at the St-Michel quarry, and whose 120°, thus accounting for the pseudohex perseverance in collecting and identifying these agonal crystal shape. Perfect basal cleavage is rare minerals has provided the main impetus evident from the persistent flaky habit of toward their study. The new mineral and name ground samples; a good cleavage normal to have been approved by the Commission on the base is visible in some SEM photographs. New Minerals and Mineral Names, I.M.A. Sabinaite is optically transparent and color Cotype specimens of sabinaite are in the Na less, biaxial negative with 2V (universal stage) tional Mineral Collection at the Geological Sur 85(5)°, a 1-74(2), 0 1.80(2), y 1.85(1). X is vey of Canada, Ottawa (61017 to 61024 in perpendicular (or nearly) to the plates. clusive), and in the Royal Ontario Museum, Sabinaite does not fluoresce in ultraviolet Toronto (M35902). radiation. However, in some specimens this inertness is obscured by the presence of films of a gibbsitc-typc mineral (No. 3 of Sabina Properties 1976, 1979) that has an intense, while fluo Physical and optical properties rescence under long-wave ultraviolet light. Sabi naite shows no reaction in dilute and concen Sabinaite occurs in silicocarbonatite in the trated (1:1) hydrochloric acid at room temper upper levels of the quarry, where it forms ature, but is readily soluble with effervescence white, powdery coatings and compact, chalky in warm HCI. Pycnometer measurement of an aggregates in vugs. The mineral is microscopi approximately 300-mg sample used for the chem cally flaky, with maximum dimensions of about ical analysis of sabinaite gave a density of 0.01 mm in width and 0.001 mm in thickness. 3.36 g/cm'. X-ray data Sabinaite is too fine grained for standard single-crystal X-ray study. Electron-diffraction patterns of flat-lying plates show a net that can be interpreted as orthogonal, with h + k = In and dm = 10.2, dm, = 6.6 A. Observed forms for sabinaite therefore become {100} and {110}, platy {001}, with cleavages {001} and {100}. Attempts to obtain the third cell para meter by tilting the plates were not successful because of multiple diffraction and reciprocal lattice streaking. Controlled tilting experiments about [100] do not give identical patterns and indicate that the unit cell is not precisely ortho- rhombic. Therefore, either monoclinic or triclinic symmetry would be possible, but the systematic hkO extinctions indicate that the cell is mono clinic. The X-ray powder pattern of sabinaite was indexed by using the orthogonal dimensions from the electron-diffraction pattern and cal Fig. 1. SEM photograph showing the typical platy culating c and (j from the powder data. Satis habit and crystal shape (top right) of sabinaite. factory indexing was obtained with c = 37.94 Bar represents 1 p.m. A, $ = 90" (Table 1). Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/18/1/25/4005447/25_18_1_cm.pdf by guest on 29 September 2021 SABINAITE, AN ANHYDROUS ZIRCONIUM-BEARING CARBONATE 27 TABLE 1. POWDER X-RAY DIFFRACTION DATA FOR SABINAITE by microprobe at CANMET, and Na,0, CO, hM. hU and F were determined by wet-chemical methods 'est neas dealc W neas dcalc at the Geological Survey of Canada. No other 10 B.97 8.974 012 1 2.243 2.244 048 i S.10 5.093 020 1 2.153 2.150 0.2.16 elements were detected by microprobe. <i 4.57 4.568 106 <IB 2.126 2.124 148 2 4.48 4.487 024 1 2.109 2.108 0.0.18 The analyses in Table 2, recalculated to 100 1 4.30 4.299 018 5 2.017 2.017 240 wt. %, yield a formula of (Na,Ca)B.M(Zr,Hf)4.,o 1 3.307 3.303 200 2 1.946 <>B 3.277 3.279 033 6 1.847 Tii.9a08.«(COs),.10, approximately Nao(Zr,Hf)4+» 2 3.252 3.254 202 2 1.824 1 3.009 3.010 131 3 1.795 Ti,Os(CO»)s assuming 33 O atoms and no F 6 2.991 2.991 036 <i 1.730 atoms. The analytically derived value of x is <»B 2.942 2.937 133 <» 1.693 <i 2.768 2.771 220 3 1.687 0.18 to 0.20, whereas the theoretical value is <)B 2.742 2.742 222 5 1.646 0.25.