👉 Astrophyllite, also known as "diamondstone", is a type of metamorphic rock that forms in the Earth's mantle. It is composed primarily of silicon dioxide (SiO2) and calcium carbonate (CaCO3), which are found in combination with other minerals such as quartz, feldspar, and mica. Astrophyllite is known for its unique appearance, which includes a distinctive pattern of crystals that appear like diamonds.
