Copiapite (Fe²⁺Fe³⁺₄(SO₄)₆(OH)₂·20 H₂O) and rozenite (Fe²⁺(SO₄)·4H₂O) are secondary hydrous sulfate minerals, mostly formed because of oxygenation and weathering events of primary sulfides on Earth. Acidophiles, including archaea and bacteria, and specifically anaerobic methanogens (methane-producing microorganisms) have been detected in regions where alteration of primary sulfide phases to secondary sulfates by weathering and oxidation processes are predominant. These secondary sulfate minerals are significant in defining past geological environments on Earth and other rocky planets such as Mars. We discuss the results of chemical and spectral analyses of copiapite and rozenite found in massive sulfide zones associated with banded iron formations (BIFs) in the Wayanad region in Kerala, southern India. The results from various spectroscopic techniques – VNIR reflectance spectroscopy, TIR (emitted radiation) and FTIR spectroscopy, Laser Raman, and X-ray diffraction were recorded and matched with the literature and databases. Different matching algorithms like Spectral Feature Fitting (SFF), Spectral Similarity Value (SSV), Modified Spectral Angle Similarity (MSAS), and Pearsonian Correlation Coefficient (PCC) were utilized to quantitatively match the reflectance spectra with reference spectra (USGS and RELAB). The genesis of copiapite and rozenite in the area occurs by seasonal and temporary development of acidic environment with the high elevations of the Wayanad plateau providing the low-humidity conditions during the dry season. Copiapite and rozenite were detected as alteration products in different regions on Mars and could provide insights into environmental conditions that prevailed during the geological evolution of Mars. Therefore, the study of copiapite and rozenite formation in a terrestrial environment will enhance our understanding of similar mineral precipitation, genesis, and fluvial processes on Mars. Future missions to Mars could also use the data obtained from the present study to calibrate similar instruments to be employed to detect these secondary sulfate minerals.

白云母（Fe ²⁺ Fe ³⁺ ₄（SO ₄）₆（OH）₂ ·20 H ₂ O）和菱锰矿（Fe ²⁺（SO ₄）·4H ₂O）是次生含水硫酸盐矿物，主要是由于地球上主要硫化物的氧化和风化作用而形成的。在风化和氧化过程占主导地位的主要硫化物相转变为仲硫酸盐的地区，已发现包括古细菌和细菌的嗜酸菌，特别是厌氧产甲烷菌（产甲烷的微生物）。这些次生硫酸盐矿物对于定义地球和其他岩石行星（如火星）的过去地质环境具有重要意义。我们讨论了在印度南部喀拉拉邦的Wayanad地区与块状铁形成（BIF）相关的块状硫化物区域中发现的铜辉石和菱锰矿的化学和光谱分析结果。各种光谱技术的结果– VNIR反射光谱，记录了TIR（发射辐射）和FTIR光谱，激光拉曼光谱和X射线衍射，并与文献和数据库相匹配。光谱特征拟合（SFF），光谱相似度值（SSV），修正光谱角相似度（MSAS）和皮尔逊相关系数（PCC）等不同的匹配算法用于将反射光谱与参考光谱（USGS和RELAB）进行定量匹配。该地区的锂辉石和菱锰矿的成因是通过酸性环境的季节性和暂时发展而实现的，Wayanad高原的高海拔为干旱季节提供了低湿度条件。在火星的不同区域中都检测到了白云母和软锌矿作为蚀变产物，它们可以提供有关火星地质演化过程中普遍存在的环境条件的见解。因此，在陆地环境中研究铜辉石和菱锰矿的形成将增进我们对火星上相似的矿物沉淀，成因和河流形成过程的理解。未来前往火星的任务也可以使用从本研究中获得的数据来校准用于检测这些次生硫酸盐矿物的类似仪器。