对我国滇西北宣威组煤中石英和二氧化硅的成因研究，有助于从根源上认识石英和二氧化硅与肺癌高发的关系。为了解决这些问题，对宣威组煤中的二氧化硅进行了矿物学和微观研究。研究结果如下：（1）晚二叠世宣威组煤层中的二氧化硅来源于碎屑输入、早成岩作用和晚成岩作用。 (2)更重要的贡献来自于早期成岩作用，其中含有丰富的自生石英和无定形二氧化硅。 (3)无机硅中的石英和二氧化硅与高岭石的共生性更强，生物硅中的石英和二氧化硅与菱镁石的共生性更强。 (4) 鉴定出煤样中的三种二氧化硅多晶型物：蛋白石-A（无定形二氧化硅）、蛋白石-CT/-C（方英石/鳞石英）和α石英。 (5) Opal-A 普遍存在，而 Opal-CT/-C 和 α 石英则很少见。 (5)Opal-A是一种无定形、无毒的普通二氧化硅。 (6) 由于无定形二氧化硅的毒性及其在煤炭中的存在是一个新兴话题，因此应对其进行持续监测。© 2023。作者获得 Springer-Verlag GmbH 德国（Springer Nature 旗下公司）的独家许可。

The study on the origin of quartz and silica in Xuanwei Formation coal in Northwest Yunnan, China, is helpful to understand the relationship between quartz and silica and the high incidence of lung cancer from the root. To address these questions, the mineralogy and microscopic studies of silica in Xuanwei Formation coal were performed. The following results were obtained: (1) silica in the late Permian Xuanwei Formation coal seams originated from detrital input, early diagenesis, and late diagenesis. (2) A more significant contribution comes from early diagenesis, which contains abundant authigenic quartz and amorphous silica. (3) Quartz and silica from inorganic silicon are more symbiotic with kaolinite and from biogenic silicon with chamosite. (4) Three silica polymorphs in coal samples have been identified: opal-A (amorphous silica), opal-CT/-C (cristobalite/tridymite), and α quartz. (5) Opal-A is ubiquitous, while opal-CT/-C and α quartz are rare. (5) Opal-A is an amorphous and nontoxic ordinary silica. (6) Since the toxicity of amorphous silica and its presence in coal is an emerging topic, it should be continuously monitored.© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.