李时珍石——一种Zn硫酸盐新矿物  

LISHIZHENITE——A NEW ZINC SULPHATE MINERAL

作　　者：李万茂[1] 陈国英[1] 

机构地区：[1]兰州大学地质系,兰州730000

出　　处：《矿物学报》1990年第4期299-305,共7页Acta Mineralogica Sinica

基　　金：国家自然科学基金

摘　　要：李时珍石是一种Zn硫酸盐新矿物,发现于我国青海省锡铁山铅锌矿床氧化带,化学分子式是ZnFe_2^(3+)(SO_4)_4·14H_2O。该矿物产于硬石膏裂隙或孔洞中,与粒铁矾、叶绿矾、自然硫、石膏、黄铁矿、石英等共生。晶体习性板状或板柱状。淡玫瑰紫色,玻璃光泽。硬度3.5,解理{010}近于完善。实测密度D_m=2.206(4)g/cm^3,计算密度D_c=2.201g/cm^3。偏光镜下无色,无多色性,2V(-)-47°;黄光中的折射率:α——1.522(2),β——1.568(1),γ——1.578(4)。空间群P(?),晶胞参数:a=6.477(1),b=15.298(3),c=6.309(1),α=90.20°(1),β=101.11°(1),γ=93.97°(1),V=611.9(1)(?)~3,Z=1。DTA曲线在119—156和740℃处有2个主要强吸热峰,在214,246,296和802℃处有4个弱吸热峰。TG曲线表明矿物在加热时,分阶段脱失结晶水,到310℃时,总失重量为30%。红外光谱在3351—3035和1131—997cm^(-1)处有2个主要吸收带;在1658—1651,667—537和484cm^(-1)处有3个次要吸收带。不同温度下测量的穆斯堡尔谱,由-Fe^(3+)离子的宽阔不对称单峰组成。Lishizhenite is a new zinc sulphate mineral with an ideal chemical formula of ZnFe_2^(3+)+(SO_4)_4·14H_2O found in the oxidation zone of a Pb-Zn deposit at Xitieshan, Qinghai Province, China. The mineral was found in a crack or cavity of anhydrite associated with roemerite, copiapite, sulphur, gypsum, pyrite and quartz. Crystals are usually tabular or tabular-prlsmatlc. Pale violet in colour and vitreous in luster. H 3.5. Cleavage {010} nearly perfect. Density by pycnometer D_(meas).=2.206(4) g/cm^3 and calculated density D_(cale).=2.201g/cm^3. Biaxial(-), 2V=47°; β=1.522(2),β=1.568(1),γ=1.578(4). Space group P, unit cell dimensions are: 6.477(1), b=15.298(3), c=6.309(1), α=90.20(1)°. β=101.11(1)°, γ=93.97(1)°, V=611.9(1)~3, Z=1. The DTA curve of the mineral . shows two endothermic peaks at 119—156 and 740℃, and four weak endothermic peaks at 214, 246, 296 and 802℃. From the thermogravimeteric curve the mineral appears to gradually lose water. Heating is accompanied by a weight loss step by step. At 310℃, the material has lost 30 wt.%. The IR absorption spectrum of the mineral has two principal absorption bands at 3351—3035 and 1131—997cm^(-1), and three subordinate bands at 1658—1651, 667—537 and 484cm^(-1). Mssbauer spectrum of the mineral measured at various temperatures consists of a broad asymmetric singlet of Fe^(3+). The mineral was named in honour of Li Shizhen——a famous ancient Chinese pharmacologist.

关 键 词：李时珍石 ZN 硫酸盐 矿物 

分 类 号：P578.7[天文地球—矿物学]