Hedan et al. (2015) recently reported an interesting method for determining the elastic modulus of vermiculite, a representative swelling clay mineral. A platy natural macrocrystal of vermiculite was used in the study. The technique combining mechanical compression and digital image correlation (DIC) appears plausible. However, a fundamental issue related to the reported testing method, particularly the experimental setup and specimen geometry constraints, arises and is worth re-examination and discussion, because it may make the reported modulus inappropriate or inaccurate. In this short discussion, the stress distribution of a thin plate such as the tested vermiculite macrocrystal under uniaxial compression is analyzed, and the reported results are re-interpreted. It appears that the reported Young's modulus of 32.3 GPa is too high for the studied vermiculite.

Hedan等。（2015年）最近报道了一种有趣的方法来确定ver石（一种代表性的膨胀黏土矿物）的弹性模量。该研究中使用了片状天然crystal石大晶。结合机械压缩和数字图像相关性（DIC）的技术似乎是合理的。但是，出现了与报告的测试方法有关的基本问题，尤其是实验设置和样品几何形状的限制，值得重新研究和讨论，因为这可能使报告的模量不合适或不准确。在简短的讨论中，分析了薄板（例如，经测试的ver石大晶体）在单轴压缩下的应力分布，并对报告的结果进行了重新解释。似乎报告的杨氏模量为32。