Background and Objectives: There are many Yemeni stones that have demonstrate different biological activities that could be used as source of promising drugs. These stones can have interesting activities .the stones Are effectiveness as antimicrobial ,antioxidant and also anti-Alzheimer's diseases .Therefore, this study will concern on the study of some selected stones as antimicrobial and anti-oxidant activities and evaluate the in vivo activity of stones as anti-Alzheimer activity. To elevate the targeted biological activities ,stones were collected based on the present of silica , aluminum and other minerals for activities .Materials and Methods : The collected stones responsible. Were studied between the period of collected stones were between December 2023 to October 2023. The stones were collected from different places in Yemen .Then the anti-microbial activity Escherichia coli , Klebsiella Staphylococcus aurous , Enterobacter , Candida were evaluated by measuring the inhibition zone and MIC(minimum inhibition zone ).The antioxidant activity were measured by determining the free radical scarving activity by DPPH. While the in- vivo activity of Orthoclase and Kaolin as anti-Alzheimer activity was elevated by measuring the behavior activity of the water maze test. Followed by conducting histopathology to the tested rats Results : The Yemeni stones show significant biological activity, and antimicrobial activity against many types of G+ and G- bacteria and candida, the stones show stronger activity against G-+ve bacteria rather than G-ve bacteria with MIC. The collected kaolin sample showed the strongest antimicrobial activity with MIC 0.424 mg and MBC 0.683mg.Evaluation of the samples as antioxidant were strong, the orthoclase showed the strongest activity. In Alzheimer's disease the orthoclase sample showed the strongest activity when compared with the standard drug Donepezil with IC50 0.081ꭒg/ml the Orthoclase and Kaolin compared with donepezil were showed promosing activity and improvement the behavioral activity at the Morris test. In while Orthoclase and Kaolin give escape latency time 15,77 second compared with standard  drug donepezil 14,9 second and non-treated mice 57,44 and normal rat 14,89 seconds. Conclusion: the results of the current study confirm the antimicrobial, antioxidant, and anti-Alzheimer disease of some Yemeni stones. The stone kaolin which was collected from Amran, Saada shows antimicrobial activity. the stone orthoclase shows good anti-oxidant activity and anti-Alzheimer disease. All biological activity achieved by stones might be associated with the presence of silicon and calcium in high concentrations