A very cool one!
Tiny
igneous, metamorphic, and sedimentary
Color and texture is one way to classify igneous rocks. Another way to do this is modal classification and normative classification.
Thomas McKenny Hughes has written: 'Notes on the classification of the sedimentary rocks' -- subject(s): Sedimentary Rocks, Classification 'Geological measures of time'
Rock classification is the process of categorizing rocks based on their physical, chemical, and mineralogical properties. This helps geologists understand the origins and characteristics of different rocks, such as sedimentary, igneous, and metamorphic rocks. Classifying rocks also aids in studying the Earth's history and geological processes.
foliated and nonfoliated
Preserved coral reefs that have turned into sedimentary rocks are classified as biogenic sedimentary rocks.
This classification scheme would likely be based on the genesis or origin of the rocks, as plutonic and metamorphic rocks are both associated with processes occurring beneath the Earth's surface (igneous intrusion and metamorphism), while sedimentary and volcanic rocks form at or near the Earth's surface through sedimentation and volcanic activity, respectively.
asial sedimentary igneous metamorphic
Even in the most generalized classification, more than two igneous rocks have phaneritic textures. In that generalized classification, they are granite, diorite, gabbro, and peridotite.
The scientific study of the physical characteristics of rocks is called petrology. It focuses on the composition, classification, and origin of rocks based on their physical and chemical properties.
A classification of metamorphic rocks would include whether they are foliated or non-foliated. Foliated metamorphic rocks, such as schist and gneiss, exhibit a layered or banded appearance due to the alignment of mineral grains under pressure. Non-foliated metamorphic rocks, like marble and quartzite, do not display such layering and are typically composed of a single dominant mineral. Other factors for classification can include the parent rock material and the conditions of temperature and pressure during metamorphism.