Sulfide Minerals硫化物矿物包括:硫化物、碲化物、砷化物·Chalcopyrite黄铜矿Chalcopyrite,CuFeS2,is the most important ore mineral of copper.Chalcopyrite(KAL-co-PIE-rite)usually occurs in massive form(非晶质)rather than in crystals,but its crystals are unusual among the sulfides in having a shape like a four-sided pyramid(四棱锥)(technically they are scalenohedra严格的说是偏三面体).It has a Mohs hardness of3.5to4,a metallic luster,a greenish black streak and a golden color that is commonly tarnished in various hues(呈各种晦暗色调)(though not the brilliant blue of bornite(斑铜矿的宝石蓝)).Chalcopyrite is softer and yellower than pyrite(黄铁矿),more brittle(脆)than gold.It is often mixed with pyrite.Chalcopyrite may have various amounts of silver(银)in place of the copper,gallium(镓)or indium(铟)in place of the iron,and selenium (硒)in place of the sulfur.Thus these metals are all by products of copper production.硬度3~4,比重4.3~4.4,解理不佳,参差状至贝壳状断口,晶体呈假四面体,常呈双晶,晶面上有条纹。
一般以致密块状、肾状过破套装集合体产出。
黄铜色,表面带有蓝紫色晕彩,条痕绿黑色。
不透明,金属光泽。
成因:形成于硫化物矿床,通常都是热液矿脉,并与磁黄铁矿、石英、方解石、黄铁矿、闪锌矿和方铅矿共生。
此外,还产生于铜矿床的蚀变。
鉴定特征:溶于硝酸,燃烧时,火焰呈绿色。
·Bornite斑铜矿Bornite(Cu5FeS4)is one of the lesser copper ore minerals,but its color makes it highly collectible.Bornite stands out for the amazing metallic blue-green color it turns after exposure to the air.That gives bornite the nickname peacock ore(孔雀铜矿).Bornite has a Mohs hardness of3and a dark gray streak.Copper sulfides are a closely related mineral group,and they often occur together.In this bornite specimen are also bits of golden metallic chalcopyrite(CuFeS2)(黄铜矿)and areas of dark-gray chalcocite(Cu2S)(辉铜矿).The white matrix (基质、充填物)is calcite(方解石).硬度3,比重5.0~5.1,极不佳解理,参差状至贝壳状断口。
晶体呈立方日、八面体或十二免提,常有弯曲或不平坦的晶面。
致密块状或粒状,铜红色、棕铜色或青铜色,风画面呈蓝色;紫色和红色斑状锖色,因而有“孔雀石”的俗名。
条痕灰黑色,不透明,金属光泽。
成因:与石英、黄铜矿和方铅矿等矿物共生于热液矿脉,也形成于某些岩浆以及铜矿的氧化带。
鉴定特征:溶于硝酸。
·Cinnabar辰砂、朱砂Cinnabar,mercury sulfide(HgS),is the principal ore of mercury(汞).Cinnabar is very dense(致密),8.1times as dense as water,has a distinctive red streak and has hardness2.5,barely scratchable by the fingernail(勉强可为指甲所刻划).There are very few minerals that might be confused with(与...混淆)cinnabar,but realgar(雄黄)is softer and cuprite(赤铜矿)is harder.硬度2.5,比重8.0~8.2,完全解理,贝壳状至参差状断口。
晶体呈厚板状、菱面体和柱状,常成双晶。
块状、皮壳状、粒状里合体。
透明~不透明,红色条痕,金刚、半金属或黯淡光泽。
成因:与雄黄、黄铁矿一起形成于火山口周围。
其他共生矿物有自然汞、白铁矿、蛋白石、石英、辉锑矿和方解石;可产于与近期火山活动有关的矿脉或沉积岩中。
鉴定特征:暴露于空气中稳定不变。
·鸡血石“鸡血石”鸡血石为朱砂(硫化汞)渗透到高岭石,地开石之中而形成,这样两者交融,共生一体的天然宝石,在国内外是极为罕见。
“鸡血石”是辰砂条带的地开石(一种含羟基的铝硅酸盐矿物),其颜色比朱砂还鲜红。
因为它的颜色像鸡血一样鲜红,所以人们俗称鸡血石。
我国最早发现的鸡血石是浙江昌化玉岩山鸡血石。
后来又发现了内蒙古赤峰市巴林右旗的巴林鸡血石。
20世纪90年代又在陕西、甘肃、四川、湖南、云南等地发现了鸡血石。
由于现在的昌化朱砂(汞矿)已近尾声,所以出产的鸡血石产量相当有限,市场价格日增不衰。
·Metacinnabar 黑辰砂Metacinnabar is mercury sulfide (HgS),like cinnabar,but it takes a different crystal form and is stable at temperatures above 600°C (or when zinc is present).It is metallic gray and forms blocky crystals (单斜晶体).黑辰砂同辰砂一样,都是汞的硫化物矿物,它们的化学成分相同但晶体结构不一样。
黑辰砂为立方(等轴)晶系闪锌矿型结构,是HgS 的低温晶型,其中的硫可被硒取代,与硒汞矿(HgSe )成完全类质同象。
黑辰砂加热后可变为三方晶系的高温晶型——辰砂。
HgS 的两种变体辰砂和黑辰砂,分别形成于碱性和酸性介质中,它们的存在可说明成矿介质的酸碱性。
黑辰砂是在酸性介质中形成。
黑辰砂(HgS 为辰砂的同质多象变体,含Hg86.2%)黑辰砂的鉴定特征:暴露于空气中稳定不变。
·Orpiment 雌黄Orpiment,As 2S 3,is a common monoclinic (单斜晶体)arsenic sulfide (硫化砷)mineral.It is used a pigment (颜料)in painting,in the production of infrared-transmitting glass,oil cloth (油布),linoleum (油毯);in semiconductors (半导体)and photoconductors (光电导体),as a pigment and in fireworks (烟火).It has a Mohs hardness of 1.5to 2and a specific gravity of 3.49.It melts at 300°C to 325°C..orange to yellow mineral that is found worldwide,and occurs as a sublimation product (升华产物)in volcanic fumaroles (火山喷出孔),lowtemperature hydrothermal veins(低温热液矿脉),hot springs (温泉)and as a byproduct (副产品)of the decay (衰变)of another arsenic mineral,realgar(雄黄).It is often found in association with realgar.It takes its name because of its deep yellow color.硬度1.5~2,比重3.4~3.5,完全解理,参差状断口。
单晶体呈板状或短柱状,集合体呈片状、肾状、土状、块状、粒状及不规则块状等。
柠檬黄色,条痕鲜黄色,透明~半透明,油脂光泽至金刚光泽,解理面呈珍珠光泽。
与自然硫相似,但自然硫不具完全解理。
成因;见于低温热液矿床,常与辉锑矿、雄黄共生,雄黄也可形成于温泉附近的沉积皮壳内。
鉴定特征:易熔,加热后释放出大蒜味气体,是含砷气体的标志性气味。
溶于硝酸并在液底留下黄色硫痕迹。
与雄黄的区别:(1)雄黄受热熔化为暗红色熔体;雌黄熔化为黄色熔体。
(2)雄黄粉末难溶于碳酸胺溶液,雌黄易溶。
(3)雄黄与雌黄的晶体面网间距d不同,故可用X射线衍射法进行鉴别。
(4)雄黄与雌黄还可用红外光谱法鉴别。
·Realgar雄黄Realgar,α-As4S4,is an arsenic sulfide mineral(硫化砷矿物),also known as"ruby sulphur"or"ruby of arsenic"(“红宝石色的硫化或砷”).It is asoft,sectile(可切的)mineral occurring in monoclinic crystals(单斜晶体),or in granular,compact,or powdery form(粒状、致密状、粉末状集合体),often in association with the related mineral(共生矿物),orpiment(As2S3)(雌黄).It is orange-red in colour(桔红色),melts at320°C,and burns with a bluish flame releasing fumes of arsenic and sulfur(用吹管氧化焰烧之,释放冒白烟,有硫、砷味).Realgar is soft with a Mohs hardnessof1.5to2and has a specific gravity of3.5.Its streak is orange colored(桔色条痕).It is trimorphous(同质三相)with alacranite andpararealgar(副雄黄)。