墨绿砷铜石与假孔雀石的中间端员组份矿物──砷假孔雀石的发现

The Discovery of Arsenopseudomalachitean Intermediate Member of Cornwallite Pseudomalachite Isomorphic Series

砷假孔雀石是墨绿砷铜石与假孔雀石的中间端员组份矿物，首先发现干中国广西德保矿区硫化铜矿床铁帽带，该物的发现使不同族的墨绿砷铜石和假孔雀石联成一类质同象系列。该物的化学成份为ＣｕＯ６３．３２％、Ａｓ２Ｏ５２２．２０％、Ｐ２Ｏ５８．９３％、ＳＯ３０．５６％、Ｈ２Ｏ５．５３％。晶体呈翠绿色粒状，斜方桂状，透明，硬度Ｈ＝４，实测比重４．５９，χ射线衍射特征强线为４．８３（５９）４．５９（９１）３．９６（４５）３．２１（９５）３．１１（１００）３．０２（９３）２．８９（６０）２．４９（６１）２．４７（９７）２．４１５（９６）１．８７８（４４）１．７９３（４４）１．７６４（４５），晶胞参数ａｏ＝１６．９５（５）、ｂ０＝５．８４（１）、Ｃ０＝４．６０（２）、β＝９３°．００（７），Ｚ＝２。单斜晶系，空间阵Ｐ２１／ａ。

Arsenopseudomalachlie was found with other secondary copper arsenate minerals in shuangwall hill, Debao mine, Guangxi China. Its chemical composition was CuO 63. 32%, As2O522. 20%, P2O5 8. 93 %, SO3 0. 56 % (by EPMA), H2O 5. 53 % (by thermal gravimetric analysis),giving a chemical formular of Cu5.00[ (A5O4) 1. 21 .(PO4 ) 0. 79 ]2. 00 (SO4 ) 0. 04 (OH )3. 85. Its crystals wereshort prism, emeral green in color, Transparent, D(mean) = 4. 59, D(calc) = 4. 61, H= 4. Average refractive index was 1. 885, the stronger lines in X-ray diffraction pattern were: 5. 51 (37)(110), 4. 83(59) (210), 4. 59 (91) (001 ), 3. 96 (45) (201 ), 3. 54(88) (111), 3. 33 (50) (211),3. 21 (95) (401), 3. 11 (100) (311), 3. 02(93) (401 ), 2. 98(55) (311), 2. 89(60) (120), 2. 74(64)(220), 2. 59 (50) (320), 2. 53 (54) (511), 2. 49 (61) (601 ), 2. 47 (97) (021 ), 2. 415 (96) (700),2. 346 (58) (221), 2. 283 (58) (321), 2. 223 (44) (321), 2. 169 (46) (611), 2. 117 (43) (800),1. 878(44) (801), 1. 794 (44) (031), 1. 770 (41) (430), 1. 764 (45) (231), 1. 756 (43) (721),1. 689 (42) (530), 1. 637 (45) (431), 1. 631 (41) (422), 1. 606 (39) (802), 1. 581 (38) (920),1. 579 (43) (821 ), 1. 549 (38) (812), 1. 517 (38) (730), 1. 453 (37) (232), 1. 441 (40) (1111),1. 440(39) (240), 1. 433 (37) (830), 1. 422 (37) (332), 1. 393 (36) (041), 1. 386 (34) (141),1. 346(35) (341), 1. 337(38) (632), 1. 331 (35) (441), calculated unit cell parameters:ao=16. 95 (5) A, bo= 5. 84 (1) A, co= 4. 60 (2 ) A, β= 93°.00 (7), and Z= 2, monoclinic system,space group: P21/a.The infrared spectra showed absorption bands at 3427, 3350, 1810 (cm-1 ) of (OH)-; at1082, 1027, 992, 611, 525 (cm-1) of (PO4)3-; at 831, 800, 770, 447 (cm-1) of (A5O4)3-,Thermal analysis showed endothermic peak at 560℃ lost 5. 53% of weight.