Perlite

Perlite, also called pearlstone is a natural glass with concentric cracks such that the rock breaks into small pearl-like bodies. It is formed by the rapid cooling of viscous lava or magma.

Bibliography

• Cox et al. (1979): The Interpretation of Igneous Rocks, George Allen and Unwin, London.
• Howie, R. A., Zussman, J., & Deer, W. (1992). An introduction to the rock-forming minerals (p. 696). Longman.
• Le Maitre, R. W., Streckeisen, A., Zanettin, B., Le Bas, M. J., Bonin, B., Bateman, P., & Lameyre, J. (2002). Igneous rocks. A classification and glossary of terms, 2. Cambridge University Press.
• Middlemost, E. A. (1986). Magmas and magmatic rocks: an introduction to igneous petrology.
• Shelley, D. (1993). Igneous and metamorphic rocks under the microscope: classification, textures, microstructures and mineral preferred-orientations.
• Vernon, R. H. & Clarke, G. L. (2008): Principles of Metamorphic Petrology. Cambridge University Press.

Foto
Concentric cracks (Perlite) in a Obsidian, Germany. PPL image, 2x (Field of view = 7mm)	Concentric cracks (Perlite) in a Obsidian, Germany. PPL image, 2x (Field of view = 7mm)	Concentric cracks (Perlite) in a Obsidian, Germany. PPL image, 2x (Field of view = 7mm)
Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)
Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)
Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)
Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)
Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)
Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)
Concentric cracks (Perlite) in a Obsidian, Greece. XPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 2x (Field of view = 7mm)
Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 2x (Field of view = 7mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 2x (Field of view = 7mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 2x (Field of view = 7mm)
Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)
Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)	Concentric cracks (Perlite) in a Obsidian, Greece. PPL image, 10x (Field of view = 2mm)