Geological & Scientific Properties | Amphibole Quartz
Amphibole Quartz, also known as Angel Phantom Quartz, is a unique and visually striking variety of quartz. It is characterized by the presence of inclusions, typically of amphibole minerals, which give it distinctive patterns and colors. Here are its key geological and scientific properties:
Chemical Composition and Structure:
- Composition: Amphibole Quartz is primarily silicon dioxide (SiO₂), which is the basic composition of quartz. The amphibole inclusions can be a mix of different minerals, including hornblende, riebeckite, tremolite, actinolite, and others.
- Crystal System: It crystallizes in the hexagonal system, typical of quartz.
Physical Properties:
- Color and Inclusions: The quartz itself is usually clear or white, while the amphibole inclusions can range from white, yellow, brown, green, to red, giving each crystal a unique appearance.
- Hardness: It shares the same hardness as pure quartz, rating a 7 on the Mohs scale.
- Luster: Amphibole Quartz typically has a vitreous (glass-like) luster.
- Transparency: This mineral can range from almost transparent to translucent, depending on the density and type of inclusions.
- Cleavage and Fracture: Like other quartz varieties, it has no cleavage and typically breaks with a conchoidal fracture.
Optical Properties:
- Refractive Index: The refractive index of Amphibole Quartz is around 1.544 to 1.553.
- Birefringence: Due to its hexagonal crystal structure, Amphibole Quartz exhibits birefringence.
Geological Occurrence:
- Formation: This type of quartz forms in igneous and metamorphic rocks. The amphibole inclusions are usually the result of metamorphic processes.
- Associated Minerals: It is often found in association with other minerals common in metamorphic environments.
Major Deposits:
- Notable deposits of Amphibole Quartz have been found in Brazil, which is a significant source for this variety of quartz.
Amphibole Quartz is highly valued in the gem and mineral world for its unique beauty and the intriguing inclusions that each specimen holds. The presence of amphibole minerals within quartz provides a fascinating glimpse into the geological processes that shape and transform minerals in the Earth's crust.
