Merrillite Ca9 NaMg(PO4 )7 IMA symbol: Mer redefined
Merrillite is a phosphate, arsenate, or vanadate mineral with the formula Ca9NaMg(PO4)7, crystallizing in the trigonal system. It has a calculated density of 3.119 g/cm3.
Crystallography Crystal system trigonal crystal systemWikidata (CC0) Space group R 3 c :H Cell (Å, °) a = 10.3444, b = 10.3444, c = 37.0182; α = 90, β = 90, γ = 120 Cell volume 3430.49 ų, Z = 6 Axial ratios 1.0000:1:3.5786calculated from COD 9017143 Source structure COD 9017143 (American Mineralogist, 2015) — 1 of 4 structures
Powder X-ray diffraction (calculated) 2θ (degrees, Cu Kα1) I/I₀ (max 100) d (Å) 2.853 2.586 3.18 1.711 3.421 5.172 I/I₀ 100 63.4 47.9 27.8 24.3 23.7
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9017143; idealized occupancies, no preferred orientation.
Physical properties Density (calculated) 3.119 g/cm³calculated from COD 9017143
Chemistry (calculated) Molecular weight 1072.8 g/molcalculated from the IMA formula Composition (wt%) Ca 33.62%, Na 2.14%, Mg 2.27%, P 20.21%, O 41.76%
Classification Nickel-Strunz (10th) 8.AC.45Wikidata (CC0) Nickel-Strunz (9th) 8.AC.45Wikidata (CC0) Dana (8th) 38.3.4.4Wikidata (CC0)
