Spectral imaging of kimberlite drill core for mineral mapping

金伯利岩是一组富含挥发物（主要是CO2）的钾质超镁铁质火成岩，其中可含有钻石作为副矿物。在全球范围内，只有不到1%的金伯利岩含有足够数量的钻石，具有经济可行性。金伯利岩的特征是明显的不均匀颗粒结构，这是由于存在于细粒基质中的巨晶和/或巨晶（主要是橄榄石）。钻石的浓度，即单一金伯利岩矿体内的钻石等级，可以在短距离内发生显著变化，这使得有效的提取过程具有挑战性。金伯利岩的结构和矿物成分的丰度极大地影响了金刚石的等级。为了可靠地预测金刚石品位，准确地确定金伯利岩中矿物组分的模态丰度和高空间分辨率是有价值的。在这一过程中，必须特别强调与钻石有遗传联系的矿物相（如幔源橄榄石粗晶）和导致金伯利岩矿石稀释的矿物/岩石成分（如围岩捕虏体）之间的区别。为了帮助这一点，我们建议使用反射光谱成像技术。使用可见光，近红外和中红外波长，我们的目标是创建准确的矿物地图图像使用反射成像光谱金伯利岩钻芯。这些图像将用于识别和标记不同的金伯利岩相，并协助对岩心进行等级评估。

Kimberlites are a group of volatile-rich (primarily CO2) potassic ultramafic igneous rocks, which can contain diamonds as an accessory mineral. Worldwide, less than 1% of the kimberlites contain diamonds in sufficient quantities to be economically viable. Kimberlites are characterized by a distinctly inequigranular texture, which results from the presence of macrocrysts and/or megacrysts (primarily olivine) that are set in a finer-grained matrix. The concentration of diamonds, i.e. the diamond grades within a single kimberlite ore body can vary substantially over short distance, which makes an efficient extraction process challenging. Diamond grades are greatly influenced by the texture of a kimberlite and by the modal abundance of its mineral constituents. For a reliable prediction of the diamond grade, it is, therefore, valuable to determine the modal abundance of the mineral components within a kimberlite accurately and with high spatial resolution. In this process, particular emphasis has to be put on the distinction between mineral phases that are genetically linked to diamonds, such as mantle-derived olivine macrocrysts, and mineral/rock components that cause a dilution of the kimberlite ore, such as country rock xenoliths. To assist with this, we propose using reflectance spectroscopy imaging technology. Using visible, near-infrared, and mid-infrared wavelengths, we aim to create accurate mineral map images using reflectance imaging spectroscopy for kimberlite drill cores. These images will be used to identify and label different kimberlite facies, and assist with the grade assessment of the drill core.