The Didim meteorite contains multiple lithologies and clasts of different petrologic types in a single stone. A mixture of H5 clasts in an unequilibrated H3 host was previously observed in Didim, according to the initial characterization reported in the Meteoritical Bulletin Database, providing an opportunity to investigate molecular composition that contains varying degree of equilibrium with varying mineralogy. We have taken a “from large scale to small scale” approach to spectroscopically investigate the chemical content of Didim. Centimeter‐scale biconical reflectance spectra show that Didim contains abundant olivine, pyroxene, and other optically active minerals, evident from a strong Band I near 0.93 µm and a weak Band II near 1.75 µm. Micrometer‐scale Raman spectroscopic investigations reveal the presence of carbonaceous material in addition to forsteritic olivine, pyroxene (augite and enstatite), feldspars, and opaque phases such as chromite and hematite. 3‐D Raman tomographic imaging shows that the carbonaceous material near chondrules extends underneath a large olivine grain, going further down toward the interior, indicating that the observed carbonaceous matter is likely indigenous. Nano‐scale infrared measurements reveal that the observed chemical materials in Didim contain spectral, and therefore, molecular, variations at the ~20 nm spatial scale. These chemical variations are normally not accessible via conventional infrared techniques, and indicate the presence of different cations in the molecular composition of observed minerals. By taking the “large scale to small scale” approach, we show that these compositional variations can be captured and investigated nondestructively in meteorites to understand formation/evolution of chemical components in the parent body.

中文翻译：

---

Didim（H3-5）陨石的双圆锥反射率，显微拉曼光谱和纳米FTIR光谱：化学成分和分子变化

Didim陨石在一块石头中包含多种岩性和不同岩石类型的碎屑。根据气象公报数据库中报道的初始特征，以前在Didim中曾观察到在未平衡的H3宿主中混合的H5碎片，这为研究包含不同平衡度和不同矿物学的分子组成提供了机会。我们采用了“从大规模到小规模”的方法，以光谱法研究了迪迪姆的化学成分。厘米级的双锥反射光谱表明，Didim含有丰富的橄榄石，辉石和其他旋光性矿物，从强I波段接近0.93 µm和弱II波段接近1.75 µm可以看出。微米级拉曼光谱研究表明，除了镁橄榄石，辉石（辉石和顽辉石），长石和不透明相（例如铬铁矿和赤铁矿）之外，还存在碳质物质。3-D拉曼层析成像显示，软骨周围的碳质物质在一个大的橄榄石颗粒之下延伸，进一步向下延伸至内部，这表明所观察到的碳质物质可能是原生的。纳米尺度的红外测量表明，在迪迪姆观察到的化学物质在〜20 nm的空间尺度上包含光谱变化，因此也包含分子变化。这些化学变化通常是无法通过常规红外技术获得的，表明观察到的矿物的分子组成中存在不同的阳离子。