What weathering product is formed when either sodium or calcium carbonate is produced instead of potassium, showing similarities to K-feldspars?

Plagioclase is a solid solution series of feldspar minerals that forms as a result of weathering processes involving sodium and calcium. When feldspars weather, they can create plagioclase, which is composed of varying proportions of sodium and calcium. This is particularly significant when considering the geology of igneous rocks, as they often contain feldspar minerals that can break down to form other types of minerals.

In this context, the question highlights the transformation of potassium feldspar under specific conditions where sodium or calcium are involved instead of potassium. This transformation is a crucial aspect of the rock weathering process, illustrating the similarity in substitute elements among feldspar minerals. Plagioclase retains the same basic aluminum silicate structure characteristic of feldspars, which makes it a logical product of the weathering of potassium-rich rocks.

Silicate minerals, in general, encompass a broad range of compounds found in the Earth's crust, but the specificity of sodium and calcium leading to plagioclase distinguishes this option. Hematite and goethite are iron oxides and are associated with different weathering pathways largely influenced by iron-rich materials, making them less relevant in this particular context where the focus is on the feldspar family and the influence of