Gypsum Caves: Gypsum caves, often known as gypsum karst caves, form throughout the dissolution of gypsum by groundwater. As slightly acidic drinking water percolates through gypsum-abundant bedrock, it steadily dissolves the gypsum, generating underground voids and passages. Gypsum may take up to a few months to break up clay soil. https://www.propanraya.com/id/produk/eco-gypsum-ee-4050