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现代地质 ›› 2025, Vol. 39 ›› Issue (01): 183-193.DOI: 10.19657/j.geoscience.1000-8527.2025.006

• 宝石地质学 • 上一篇    下一篇

吉林“磐龙墨玉”的宝石矿物学、年代学及成因研究

安雯静1(), 白峰1(), 刘孟松1, 张道元1, 黄甜甜1, 王雯2   

  1. 1.中国地质大学(北京)珠宝学院,北京 100083
    2.吉林省三河矿业开发有限公司,吉林 长春 130000
  • 出版日期:2025-02-10 发布日期:2025-02-20
  • 通信作者: 白 峰,男,教授,博士生导师,1971年出生,主要从事宝石学、矿物学、岩石学和矿床学的教学和科研工作。Email: baifeng@cugb.edu.cn
  • 作者简介:安雯静,女,硕士研究生,2001年出生,地质学专业,主要从事宝石矿物学方面研究。Email: 1416333191@qq.com
  • 基金资助:
    吉林省磐龙玉分类与质量评价研究科研项目(77932020019)

Gem and Mineralogy, Chronology and Genesis of “Panlong Dark Jade” from Jilin Province

AN Wenjing1(), BAI Feng1(), LIU Mengsong1, ZHANG Daoyuan1, HUANG Tiantian1, WANG Wen2   

  1. 1. School of Gemology, China University of Geosciences (Beijing), Beijing 100083, China
    2. Jilin Sanhe Mining Exploiting Co., Ltd, Changchun, Jilin 130000, China
  • Published:2025-02-10 Online:2025-02-20

摘要:

本研究旨在系统探讨吉林“磐龙墨玉”的宝石矿物学特征、成因及其地质背景,以揭示该玉石的形成机制,填补该领域的研究空白。综合运用常规宝石学测试、多种光谱分析技术(包括X射线衍射(XRD)、激光拉曼光谱、红外光谱)、全岩化学分析以及激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)等多种方法,对吉林省中东部中型铅锌矿矿体围岩中发现的“磐龙墨玉”进行了研究。结果表明,“磐龙墨玉”的折射率介于1.53和1.54之间,相对密度为2.73至2.79,摩氏硬度则在3.89至6.23之间。其主要矿物成分为石英和绢云母,并包含绿泥石、磁黄铁矿和钛铁矿等次要矿物,结构特征包括独特的板状与块状构造以及超糜棱、隐晶质及变余结构。致色矿物以石墨和绿泥石为主。稀土元素的总量变化范围为177.93×10-6至216.89×10-6,轻稀土元素明显富集,而Eu元素则呈现显著的亏损。锆石U-Pb年龄测定显示为(331.3±2.3) Ma(中石炭世)。结合区域构造背景及地质资料分析,推测“磐龙墨玉”的原岩为正常沉积岩,经历了区域变质作用形成碳质板岩,并进一步通过热液蚀变转化而成。

关键词: “磐龙墨玉”, 宝石矿物学, 地球化学, 锆石U-Pb定年, 绿泥云英质玉石

Abstract:

This study systematically explores the gemological properties, genesis, and geological context of “Panglong Dark Jade”, aiming to elucidate its formation mechanisms and address existing research deficiencies in this area. Utilizing a multifaceted approach, we employed conventional gemological testing alongside various spectroscopic methods such as X-ray diffraction (XRD), laser Raman spectroscopy, and infrared spectroscopy as well as whole-rock chemical analysis and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for zircon U-Pb dating. Our focus was on “Panglong Dark Jade” discovered in the surrounding rocks of a medium-sized lead-zinc ore deposit in the east-central region of Jilin Province. The findings reveal that “Panglong Dark Jade” has a refractive index ranging from 1.53 to 1.54, a relative density of 2.73 to 2.79, and a Mohs hardness between 3.89 and 6.23. The primary mineral constituents are quartz and sericite, potentially accompanied by accessory minerals such as chlorite, pyrrhotite, and ilmenite. Its structural characteristics are marked by distinct slaty and massive forms, in addition to supermylonitic, aphanitic, and palimpsest textures. The main chromogenic minerals are predominantly graphite and chlorite. The total concentration of rare earth elements fluctuates between 177.93×10-6 and 216.89×10-6 revealing a significant enrichment of light rare earth elements alongside a pronounced deficit of Europium (Eu). Zircon U-Pb dating yields an age of (331.3±2.3) Ma, corresponding to the Middle Carboniferous Epoch. Integrating regional structural analyses with geological data suggests that the parent rock of “Panglong Dark Jade” is a normal sedimentary rock that underwent regional metamorphism to form carbonaceous slate, subsequently modified by hydrothermal activity to produce “Panglong Dark Jade”.

Key words: “Panlong Dark Jade”, gemological mineralogy, geochemistry, zircon U-Pb dating, chlorite-mica-quartz jade

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