Yellow diamonds from the CH-7 (Chidliak) and the Misery (Ekati Mine) kimberlites in northern Canada are characterised for their nitrogen characteristics, visible light absorption, internal growth textures, and carbon isotope compositions. The diamonds are generally nitrogen-rich, with median N contents of 1230 (CH-7) and 1030 at.ppm (Misery). Normally a rare feature in natural diamonds, single substitutional nitrogen (C centres) and related features are detected in infrared absorption spectra of 64% of the studied diamonds from CH-7 and 87% from Misery and are considered as the major factor responsible for their yellow colouration. Episodically grown diamonds, characterised by colourless cores containing some nitrogen in the fully aggregated form (B centres) and yellow outer layers containing C centres, occur at both localities. Carbon isotope compositions and N contents also are significantly different in such core and rim zones, documenting growth during at least two temporally distinct events and involving different diamond forming fluids. Based on their nitrogen characteristics, both the yellow diamonds and yellow rims must have crystallized in close temporal proximity (<<1 Ma) to kimberlite activity at CH-7 and Misery.

中文翻译：

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带有无色核心的黄色钻石——加拿大 Chidliak 和 Ekati 矿下钻石生长的证据

来自加拿大北部 CH-7 (Chidliak) 和 Misery (Ekati Mine) 金伯利岩的黄钻具有氮特征、可见光吸收、内部生长纹理和碳同位素组成。钻石通常富含氮，中值 N 含量为 1230 (CH-7) 和 1030 at.ppm (Misery)。通常天然钻石中的罕见特征、单置换氮（C 中心）和相关特征在 64% 来自 CH-7 的研究钻石和 87% 来自 Misery 的研究钻石的红外吸收光谱中被检测到，并被认为是造成它们的主要因素黄色着色。随机生长的钻石的特点是无色核心包含一些完全聚集形式的氮（B 中心）和黄色外层包含 C 中心，出现在这两个位置。这些核心和边缘区域的碳同位素组成和 N 含量也有显着差异，记录了至少两个时间不同事件期间的生长，并涉及不同的钻石形成流体。根据它们的氮特征，黄色钻石和黄色边缘都必须在与 CH-7 和 Misery 的金伯利岩活动相近的时间 (<<1 Ma) 中结晶。