摘要
氯氧镁铝石(Koenenite)是一种少见矿物,最初发现于德国Gottingen。后来,F.里勒(F.Rinne)、R.库恩(R.Kuhn)、H.-H.洛斯(H.-H.Lohse)、R.奥勒曼)R.Allmann)等人先后都作过报导,而在我国还是首次发现。氯氧镁铝石结构比较特殊,性质上是一个多变的矿物。
Koenenite[4NaCl.4(Mg, Ca)Cl_(2).5Mg(OH)24Al(OH)3]from syrinite ore deposit, Jiangcheng, Yunnan is light yellow in color, and becomes dark brown due to weathering.It is foliate with cleavage {0001}perfect. The specific gravity is 1.82-2.08, after soaking in water it reduces to 1.97.The hardness is 2.06-2.1. No=1.529, reddish brown. Ne=1.557, colorless. Ne-No=0.028 .It shows weakly, biaxial 2V<10. The X-ray powder pattern of the mineral has strongest lines: 5.45(90), 3.25(50), 2.812(100), 2.380(70), 2.130(60). Koenenite consists of two trigonal substructure layers:[Na_(4)(Ca,Mg)_(2)Cl12]^(4-)andCMg7Al4(OH)22]4+. The Cl-lattice unit cell has parameters: a = 4.070A,c=32.646A, v = 541.23A3,space group R3m. The OH-lattice unit cell has parameters:a=3.051A,c=10.882A, v= 101.132A^(3), space group P3ml. The structure of koenenite, as viewed along c axis is one of regularly alternating NaCl-like chlorine and brucite-like OH double layers. All possible octahedral sites are randomly occupied by the metal ions. The strongest lines of the X-ray powder pattern for the material formed by soaking koenenite in water are. 7.73(90) ,3.835(100) ,2.570(70) ,2.285(80) , 1,935(80),1.526(80),1.495(70),1.316(50),1.269(60), 1.200(50), 0.975 (50).The unit cell parameters a=3.048A, c = 23.190A, v=186.578A3, space groupR. Chemical analysis of a water absorbed product after soaking koenenite in water gave:SiO2 0.63,Fe_(2)O_(3) 0.96,Al_(2)O_(3) 23.98,CaO0.18,MgO 32.49,MnO 0.17,H2O 25.30, Cl 15.52,sum 99.23%, leading to the formula;[Mg_(7)Al_(4)(OH)_(22)][Cl_(4)-H_(2)O].
作者
刘金定
刘群
Liu Jinding;Liu Qun
出处
《岩矿测试》
CAS
1984年第2期131-136,I0008,I0009,共8页
Rock and Mineral Analysis
