Ureilite meteorites contain iron silicide minerals including suessite (Fe,Ni)₃Si, hapkeite (Fe₂Si) and xifengite (Fe₅Si₃). Despite occurring mostly in brecciated varieties presumed to be derived from the regolith of the ureilite parent asteroid, suessite has also been confirmed in one lithology of a dimict ureilite (NWA 1241). In contrast, Si-bearing Fe-metals occur in both brecciated and unbrecciated ureilites, implying that they were formed throughout the ureilite parent asteroid. We examined major, minor and trace element data of Fe-metals in seven brecciated ureilites (DaG 319, DaG 999, DaG 1000, DaG 1023, DaG 1047, EET 83309, and EET 87720) in addition to the dimict ureilite NWA 1241.

In this study we show that the silicides and Si-bearing metals in ureilites have similar siderophile trace element patterns; therefore, the precursors to the silicides were indigenous to the ureilite parent body. Si-free kamacite grains in brecciated ureilites show flatter, more chondritic siderophile element patterns. They may also be derived from the interior of the ureilite parent body, but some may be of exogenous origin (impactor debris), as are rare taenite grains.

On Earth, iron silicides are often formed under high-temperature and strongly reducing conditions (e.g. blast furnaces, lightning strikes). On the Moon, hapkeite (Fe₂Si) and other silicides have been found in the regolith where they were formed by impact-induced space weathering. In the Stardust aerogel, iron silicides derived from comet Wild2 were also formed by an impact-related reduction process. Silicides in ureilite regolith breccias may have formed by similar processes but ureilites additionally contain abundant elemental carbon which probably acted as a reducing agent, thus larger and more abundant silicide grains were formed than in the lunar regolith or cometary material. The origin of suessite in NWA 1241 may be analogous to that of reduced lithologies in the terrestrial mantle, although a regolith origin may also be possible since this sample is shown here to be a dimict breccia.

珍珠岩陨石包含硅化铁矿物，包括苏铁矿（Fe，Ni）₃ Si，钙锰矿（Fe ₂ Si）和锡峰石（Fe ₅ Si ₃）。尽管大部分发生在角砾岩变种中，推测该角砾岩变种可能是由苏伊利石母体小行星的重生岩衍生而来的，但苏铁矿也已在一种微细苏伊利石的岩性中得到证实（NWA 1241）。相反，含硅的铁金属同时存在于角砾石和未角砾的尿素石中，这意味着它们形成于整个尿素石母体小行星中。除了二水苏莱石NWA 1241外，我们还检查了七个角砾状尿素矿（DaG 319，DaG 999，DaG 1000，DaG 1023，DaG 1047，EET 83309和EET 87720）中铁金属的主要，次要和微量元素数据。

在这项研究中，我们表明，硅藻土中的硅化物和含硅金属具有相似的嗜铁性痕量元素模式。因此，硅化物的前体是脲体母体固有的。角砾状的纤铁矿中的无硅的金刚石晶粒显示出更平坦，更呈软骨状的嗜铁元素形态。它们也可能来自尿素石母体的内部，但也可能是外源性的（撞击碎片），稀有的en石晶粒也是如此。

在地球上，通常在高温且强烈还原的条件下（例如高炉，雷击）形成硅化铁。在月球上，方铁石（Fe ₂硅酸盐和其他硅化物已在重晶石中发现，它们是由撞击引起的空间风化形成的。在星尘气凝胶中，还通过与撞击有关的还原过程形成了来自Wild2彗星的硅化铁。硅藻土角砾岩角砾岩中的硅化物可能是通过类似的过程形成的，但硅藻土还含有丰富的元素碳，可能起还原剂的作用，因此形成的硅化物晶粒比月球体或彗星物质中更大，更丰富。NWA 1241中的苏铁矿的起源可能类似于地幔中岩性的减少，尽管重灰石的起源也可能是可能的，因为此处的样品显示为角砾岩角砾岩。