Final answer:
Talc and phlogopite differ in structure and chemical composition. Talc has a sheet-like structure with magnesium and silica layers, while phlogopite has a similar structure with additional potassium ions between the layers.
Step-by-step explanation:
Talc and phlogopite differ both in terms of their structure and chemical composition.
Talc is a mineral that belongs to the phyllosilicates group. It has a sheet-like structure, consisting of layers of silica tetrahedra bonded to layers of magnesium oxide/hydroxide. This structure gives talc its characteristic softness and lubricating properties. Talc has a chemical formula of Mg3Si4O10(OH)2.
On the other hand, phlogopite is a member of the mica group of minerals. It has a layered structure similar to talc, but with additional potassium ions in between the layers. Phlogopite has a chemical formula of KMg3AlSi3O10(OH)2.