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作为异性石族矿物新种凤成石是首个该族已知成员中N(5)位贫Na且以空位居优的类似物,其理想化学式为:Na_(12)□_3Ca_6(Fe~(3+),□)_3Zr_3Si(Si_(25)O_(73))(H_2O)_3(OH)_2。它发现于我国东北辽宁省凤城市赛马钠质碱性正长岩内,多呈它形-半自形晶产出,单个晶体粒径1~7mm,最大粒径者>1.5cm。与之共生的矿物有微斜长石、正长石、钠长石、霞石和钠角闪石亚族矿物、霓石、榍石和闪叶石族矿物、“贫钠的层硅钛铈矿”(“Napoor rinkite”)、钛铌钙铈矿、钠锆石、锆石、铁金云母、氟磷灰石、富稀土的羟硅磷灰石和何作霖矿等。矿物为半透明-透明,玻璃光泽,条痕白色,性脆,摩氏硬度约5,偶见不完全解理和裂开,一轴晶正光性。N_e=1.607,N_o=1.603。凤成石属三方晶系,具R3m空间群;a=1.42467(6)nm,c=3.00330(2)nm,V=5.27908(50)nm~3,Z=3。6条强粉晶衍射线[面网间距(衍射强度)(指标化)]是:0.7186(55)(110),0.5761(44)(113),0.4187(53)(123),0.3201(47)(028),0.2978(61)(135)和0.2857(100)(044)。16点矿物成分的电子探针等分析均值为:Na_2O 11.64%,K_2O 0.52%,CaO 8.96%,MgO 0.07%,SrO_3.53%,BaO 0.02%,MnO0.10%,FeO 0.69%,Mn_2O_30.92%,Fe_2O_35.98%,La_2O_30.12%,Ce_2O_30.23%,Nd_2O_30.13%,Sc_2O_30.01%,TiO_20.38%,ZrO_211.72%,Nb_2O_50.23%,SiO_251.73%,Cl 1.13%,H_2O 2.09%,O≡Cl-0.26%,总量100.14%。根据晶体结构精测和(O+OH+F+Cl)=78计算的矿物经验化学式:[(Na_(3.00)Na_(3.00))Σ_(6.00)(Na_(5.28)K_(0.33)□_(0.39))]_(12.00)□_(2.71)Sr_(0.20)REE_(0.09))_(3.00)Ca_(4.80)Sr_(0.82)Fe_(0.29)~(2+)Mg_(0.05)Mn_(0.04)~(2+))_(6.00)(Fe_(2.25)~(3+)Mn_(0.35)~(3+)Cr_(0.08)□_(0.32))_(3.00)(Zr_(2.86)Ti_(0.09)Nb_(0.05))_(3.00)(Si_(0.87)Ti_(0.05)□_(0.08))_(1.00)Si_(1.00)(Si_(24.00)O_(72.00))[(H_2O)_(2.93)O_(1.00)(OH)_(0.07)]_(3.00)[(OH)_(1.04)Cl_(0.96_]_(2.00)。矿物实测密度2.93g/cm~3;计算密度2.88g/cm~3。基于野外和室内研究,借鉴有关合成异性石族矿物的实验资料,凤成石由一类富REE、U、Th、Zr、和挥发分的钠质碱性正长岩岩浆直接结晶而成。
As a new type of heterosexual mineral, Fengcheng Stone is the first analogue of N (5) -level Na depleted in the first known member of this group. The ideal chemical formula is Na_ (12) __3Ca_6 (Fe ~ (3 +), □) _3Zr_3Si (Si_ (25) O_ (73)) (H_2O) _3 (OH) _2. It is found in the caustic soda alkaline albite in Fengcheng City, northeastern China, mostly in the shape of a semicircle, with a single crystal size of 1 to 7 mm and a maximum particle size of> 1.5 cm. The symbiotic minerals include plagioclase, orthoclase, albite, nepheline and sodium hornblendite minerals, aegirine, gallstone, and flakeite minerals, “sodium-depleted tossosilicates (”Napoor rinkite"), titanostatite, sodium zircon, zircon, iron phlogopite, fluorapatite, hydroxy-silicon apatite rich in earth and He Zuolin mine. Minerals are translucent - transparent, shiny glass, streaks of white, brittle, Mohs hardness of about 5, occasionally incomplete cleavage and cleavage, uniaxial crystal positive phototropism. N_e = 1.607, N_o = 1.603. Fengchengshi is a trigonal system with R3m space group; a = 1.42467 (6) nm, c = 3.00330 (2) nm, V = 5.27908 (50) nm ~ 3 and Z = 3.6 strong powder diffraction lines [Surface area pitch (diffraction intensity) (indexed)] is: 0.7186 (55) (110), 0.5761 (44) (113), 0.4187 (53) (123), 0.3201 (47) (028), 0.2978 ) (135) and 0.2857 (100) (044). The 16-point mineral composition of the electronic probe and other analytical means are: Na 2 O 11.64%, K 2 O 0.52%, CaO 8.96%, MgO 0.07%, SrO 3.53%, BaO 0.02%, MnO 0.10%, FeO 0.69%, Mn 2 O 30.92 %, Fe 2 O 35.98%, La 2 O 30.12%, Ce 2 O 30.23%, Nd 2 O 30.13%, Sc 2 O 30.01%, TiO 20.38%, ZrO 2 11.72%, Nb 2 O 50.23%, SiO 2 251.73% , H_2O 2.09%, O ≡ Cl-0.26%, the total amount of 100.14%. According to the crystal structure and (O + OH + F + Cl) = 78, the empirical formula of mineral is: [(Na_ (3.00) Na_ (3.00)) Σ_ (6.00) (Na_ (5.28) K_ (0.33) 0.39) _ (12.00) __ (2.71) Sr_ (0.20) REE_ (0.09)) _ (3.00) Ca_ (4.80) Sr_ (0.82) Fe_ (0.29) ~ (2+) Mg_ (0.05) Mn_ (0.04) ) (6) Fe_ (2.25) ~ (3+) Mn_ (0.35) ~ (3+) Cr_ (0.08) __ (0.32)) _ (3.00) (0.09) Nb_ (0.05)) _ (3.00) (Si_ (0.87) Ti_ (0.05) __ (0.08)) _ (1.00) Si_ (1.00) (Si_ (24.00) O_ (72.00) (2.93) O_ (1.00) (OH) _ (0.07)] _ (3.00) [(OH) _ (1.04) Cl_ (0.96 _] _ (2.00) .The measured density of mineral is 2.93 g / cm ~ g / cm ~ 3. Based on the field and laboratory studies, drawing on the experimental data on the synthesis of heterosexual fossil minerals, Fengcheng stone is composed of a series of Na-type alkaline syenite magmas rich in REE, U, Th, Zr and volatile Direct crystallization from.