This study reports the natural radioactivity of characteristic rocks found in the historic Jeroným Mine of the Czech Republic as measured under the laboratory conditions. The rocks analyzed included granites and schists weathered to varying degrees and collected from different levels of the underground workings of the Jeroným Mine. The mine itself has been subject to metal extraction (mainly tin and tungsten) since the sixteenth century and has recently been developed as a cultural and scientific attraction open to the public. Activity concentrations of ⁴⁰K, ²³²Th and ²³⁸U were measured from nine rock samples using gamma-ray spectrometry. The activity concentrations of ⁴⁰K varied from 595 Bq kg⁻¹ to 1244 Bq kg⁻¹, while ²³²Th varied from 25 Bq kg⁻¹ to 55 Bq kg⁻¹. The activities associated with ²³⁸U ranged from 46 Bq kg⁻¹ to 386 Bq kg⁻¹. The measured activities were used to estimate two radiation hazard indices typically applied to building materials, the activity concentration index I and the external hazard index H_ex. Mean respective values of 1.02 and 0.77 for I and H_ex indicate that the rocks found in the Jeroným Mine meet radiological safety standards for building materials and do not pose a risk to potential tourists and staff.

这项研究报告了在实验室条件下测量的捷克共和国历史悠久的 Jeroným 矿中发现的特征岩石的天然放射性。所分析的岩石包括风化程度不同的花岗岩和片岩，这些岩石是从 Jeroným 矿井不同层次的地下工程中收集的。自 16 世纪以来，矿山本身一直在进行金属提取（主要是锡和钨），最近已发展成为一个向公众开放的文化和科学景点。⁴⁰ K、²³² Th 和²³⁸ U 的活度浓度是使用伽马射线光谱法从九个岩石样品中测量出来的。⁴⁰ K的活性浓度从 595 Bq kg ^-1不等到 1244 Bq kg ^-1，而²³² Th 从 25 Bq kg ^{-1 变化}到 55 Bq kg ^-1。与²³⁸ U相关的活动范围从 46 Bq kg ^-1到 386 Bq kg ^-1。测量的活动用于估计两个通常应用于建筑材料的辐射危害指数，即活动浓度指数I和外部危害指数H _ex。I和H _{ex 的}平均值分别为 1.02 和 0.77 表明在 Jeroným 矿发现的岩石符合建筑材料的放射性安全标准，不会对潜在游客和工作人员构成风险。