paragonite
Học thuậtThân thiện
Definition
Noun: A colorless or pale brown mineral belonging to the mica group, characterized by its sodium content. It is a phyllosilicate mineral, often found in metamorphic rocks.
Usage
Paragonite is used specifically as a mineralogical term. It names a distinct mineral species within the mica family, differentiated from the more common potassium-rich mica, muscovite, by its dominant sodium content.
Examples
- Noun:
- The schist sample contained significant amounts of paragonite alongside quartz.
- Under the microscope, the pale, flaky crystals were identified as paragonite.
- The chemical analysis confirmed the mica was paragonite, not muscovite.
Advanced Usage
- In Petrology/Geology: The presence of paragonite is an important indicator of specific pressure and temperature conditions during metamorphism, particularly in blueschist and eclogite facies rocks.
- The assemblage paragonite + glaucophane + garnet is typical for high-pressure metamorphism.
Variants and Related Words
- Mica (n): The broader group of silicate minerals to which paragonite belongs, known for perfect basal cleavage.
- Muscovite (n): The potassium-dominant analogue of paragonite, a very common light-colored mica.
- Phyllosilicate (n): A class of silicate minerals with a sheet-like structure, which includes micas like paragonite.
Synonyms
- Sodium mica: A descriptive synonym highlighting its chemical composition.
Notes on Meaning
This word has a single, highly specific scientific meaning. It is not used in general language, idioms, or phrasal verbs. Its usage is confined to geology, mineralogy, and related earth sciences.
Noun
- a colorless or pale brown mica with sodium