NirViaje
commented
5 years ago 
Asteroids Composition
Project+RAMA+NIAC+Phase+I+Final+Report, p25
- C型小行星：碳质球粒陨石，含水含有机物，榨干后的残渣含5到30%金属(铁镍球粒)。
- S型小行星：
- M型小行星：铁陨石，铁，10%镍, 1~10ppm铂，5%数量，光谱难以识别。
- A型小行星：橄榄铁陨石，约50%金属，某些样品有1000ppm铼，1/300数量，光谱特殊。
Asteroid Retrieval Feasibility Study, Keck Inst, 2012
- 魏德曼花紋 镍纹石是在熔点以下的温度均匀混合的铁和镍合金。在温度900到600 °C（与镍的含量相关），有两种镍含量不同的稳定合金：锥纹石的镍含量低（只有5%至15%的镍），镍纹石的镍含量高（可以高达50%）。八面体陨铁陨石的镍含量规范需要介于锥纹石和镍纹石之间，这会导致锥纹石在缓慢降温的条件下，锥纹石板会在镍纹石的晶格中沿着某一个晶轴平面的方向成长。 由于以极端缓慢的速率冷却（经历数百万年），镍铁晶体在固体内增长的长度只有几釐米。这种花纹的存在是材料来自外太空的证明，可以很容易的确定一小块的碎片是否陨石的一角。
- 八面体陨铁 在锥纹石和镍纹石的片状结构间的空隙，经常可以找到称为合纹石的微细混合物。一种铁镍磷化物，磷铁石，经常出现在镍-铁陨石中，还有镍-铁-钴、碳化钙、钴碳铁陨石、石墨和陨硫铁都会呈现几个釐米大的圆角结节 [1]。
- 陨硫铁 在地球自然的矿物中也可以找到陨硫铁，但在陨石中，特别是来自月球和火星的陨石，更为丰富。在2013年2月15日袭击俄罗斯的陨石标本中发现的矿物之一就是陨硫铁[4]。阿波罗、维京人、火卫一的太空探测器都已经证实陨硫铁存在于这些天体上。硫的同位素在陨石和地球上矿物的相对强度是相当确定的，因此代亚布罗峡谷陨石被选为国际的硫同位素比例的标准。
https://en.wikipedia.org/wiki/Iron_meteorite#Chemical_classification In 2006 iron meteorites were classified into 13 groups (one for uncategorized irons):[2]
- IAB
- IA: Medium and coarse octahedrites, 6.4-8.7% Ni, 55-100 ppm Ga, 190-520 ppm Ge, 0.6-5.5 ppm Ir, Ge-Ni correlation negative.
- IB: Ataxites and medium octahedrites, 8.7-25% Ni, 11-55 ppm Ga, 25-190 ppm Ge, 0.3-2 ppm Ir, Ge-Ni correlation negative.
- IC
- IIAB
- IIA: Hexahedrites, 5.3-5.7% Ni, 57-62 ppm Ga, 170-185 ppm Ge, 2-60ppm Ir.
- IIB: Coarsest octahedrites, 5.7-6.4% Ni, 446-59 pm Ga, 107-183 ppm Ge, 0.01-0.5 ppm Ir, Ge-Ni correlation negative.
- IIC: Plessitic octahedrites, 9.3-11.5% Ni, 37-39 ppm Ga, 88-114 ppm Ge, 4-11 ppm Ir, Ge-Ni correlation positive
- IID: Fine to medium octahedrites, 9.8-11.3%Ni, 70-83 ppm Ga, 82-98 ppm Ge, 3.5-18 ppm Ir, Ge-Ni correlation positive
- IIE: octahedrites of various coarseness, 7.5-9.7% Ni, 21-28 ppm Ga, 60-75 ppm Ge, 1-8 ppm Ir, Ge-Ni correlation absent
- IIIAB: Medium octahedrites, 7.1-10.5% Ni, 16-23 ppm Ga, 27-47 ppm Ge, 0.01-19 ppm Ir*
- IIICD: Ataxites to fine octahedrites, 10-23% Ni, 1.5-27 ppm Ga, 1.4-70 ppm Ge, 0.02-0.55 ppm Ir
- IIIE: Coarse octahedrites, 8.2-9.0% Ni, 17-19 ppm Ga, 3-37 ppm Ge, 0.05-6 ppm Ir, Ge-Ni correlation absent
- IIIF: Medium to coarse octahedrites, 6.8-7.8% Ni,6.3-7.2 ppm Ga, 0.7-1.1 ppm Ge, 1.3-7.9 ppm Ir, Ge-Ni correlation absent
- IVA: Fine octahedrites, 7.4-9.4% Ni, 1.6-2.4 ppm Ga, 0.09-0.14 ppm Ge, 0.4-4 ppm Ir, Ge-Ni correlation positive
- IVB: Ataxites, 16-26% Ni, 0.17-0.27 ppm Ga, 0,03-0,07 ppm Ge, 13-38 ppm Ir, Ge-Ni correlation positive
- Ungrouped meteorites. This is actually quite a large collection (about 15% of the total) of over 100 * meteorites that do not fit into any of the larger classes above, and come from about 50 distinct parent bodies.
Additional groups and grouplets are discussed in the scientific literature:
- IIG: Hexahedrites with coarse schreibersite. Meteoric iron has low nickel concentration.[18]
https://en.wikipedia.org/wiki/Sikhote-Alin_meteorite
Phosphorus is very common in meteorites, but in much greater concentrations than in steels. When the phosphorus level exceeds about 0.06 weight %, which is quite common in meteorites, phosphides are formed. They have a tetragonal type crystal structure with the general formula (Fe,Ni)3P but different morphologies are observed. Schreibersite is the name given to globular shaped phosphides in meteorites. Their size is a function of the phosphorous content. Schreibersite has a variable nickel content, depending upon the temperature at which they nucleated, from about 10 to 50% Ni. The higher nickel content particles tend to be smaller in size and they are more ductile than the larger, lower Ni particles, which are often cracked. https://vacaero.com/information-resources/metallography-with-george-vander-voort/1307-metallography-of-iron-nickel-meteorites-part-1-background.html
tho
Asteroid Detection
Methodology
How to find metal-rich asteroids https://arxiv.org/abs/1403.6346
How Many Ore-Bearing Asteroids? https://arxiv.org/abs/1312.4450
Observation Resource
Ground
Space
Deep space detector #25
Database and visualization