盛稀珍藏藝術品精品推薦 定向球形隕石
隕石的一種。也有人稱作石鐵隕石，這類隕石中硅酸鹽與鎳鐵合金的含量各占50%。定向又分為兩個子類：橄欖隕石與中鐵隕石。 根據硅酸鹽礦物成分特征,將石鐵隕石劃分為4種:①橄欖隕鐵(類型符號P)，主要由橄欖石和組成基質的鐵鎳金屬構成；②中鐵隕石(M),主要由斜長石、輝石和鐵鎳組成;③古銅-鱗英鐵隕石(S)，主要由鐵鎳、古銅輝石和鱗石英組成；④橄欖-古銅鐵隕石(Lo),主要由鐵鎳、橄欖石和古銅輝石構成。橄欖隕鐵中鐵鎳金屬的Ni含量約為8～15%,其成分與八面體鐵隕石相似,橄欖石的成分為Fa12-22（橄欖石中的鐵橄欖石分子的百分數），橄欖隕鐵的冷卻速率比八面體鐵隕石低，認為它可能是來自隕石母體或小行星內部更深處。占隕石數量的2%～4%，鐵鎳和硅酸鹽礦物含量相當(30%～65%)。主要礦物有橄欖石、各種輝石、鐵紋石和鎳紋石。
A type of meteorite. Others are called iron meteorites, which contain 50% silicate and 50% ferronickel. Orientation can be further divided into two subgroups: olivine meteorite and mid-iron meteorite. According to the composition characteristics of silicate minerals, the iron meteorites are divided into four types: 1) olivine meteorite (type symbol P), which is mainly composed of olivine and iron-nickel metals forming the matrix; 2) medium iron meteorite (M), which is mainly composed of plagioclase, pyroxene and iron-nickel; and 3) paleocopper-scale iron meteorite (S), which is mainly composed of iron-nickel, paleocopper-pyroxene and scale quartz; (4) Olive-bronze iron meteorite (Lo) is mainly composed of iron and nickel, olivine and bronze pyroxene. The content of Ni and Fe in olivine meteorite is about 8-15%. Its composition is similar to that of octahedral iron meteorite. The composition of olivine is Fa12-22 (the percentage of olivine molecule in olivine). The cooling rate of olivine meteorite is lower than that of octahedral iron meteorite. It is thought that olivine meteorite may come from the deeper interior of meteorite matrix or asteroid. It accounts for 2%-4% of meteorites, and the contents of iron, nickel and silicate minerals are comparable (30%-65%). The main minerals are olivine, various pyroxenes, ferrite and nickel.
大多數定向隕石的密度約5.5～6克/厘米^3。在金屬鐵鎳合金中，含鎳量多為12%～14%，故出現維德曼構造。也有人根據礦物組成將其劃分為橄欖石石鐵隕石、古銅輝石鱗石英定向隕石、古銅輝石橄欖石定向隕石和輝石斜長石定向隕石四類。
The density of most directional meteorites is about 5.5-6 g/cm^3. In ferronickel alloys, the content of nickel is 12%-14%, so the Widmann structure appears. According to mineral composition, it is also divided into four types: olivine iron meteorite, paleo-copper pyroxene squamatte oriented meteorite, paleo-copper pyroxene olivine oriented meteorite and pyroxene plagioclase oriented meteorite.
