Shards

Volcanic glass shards are fragments of the molten part of magma that cooled and solidified during eruption. Glass shards are typically remnants of tiny gas bubbles that developed and grew in size during the final ascent toward the surface; such shards may consist of many gas bubbles or only a portion of a single gas bubble. During eruption, the expanding gas broke the bubbles and surrounding glass into shards of various sizes and shapes. Shards formed by phreatomagmatic eruptions often have a particularly angular shape resulting from the violent explosive interaction between magma and water.

Bibliography



• E. WM. Heinrich (1956): Microscopic Petrografy. Mcgraw-hill book company,inc
• David Shelley (1983): Igneous and metamorphic rocks under the microscope. Campman & Hall editori.
• Vernon, R. H. & Clarke, G. L. (2008): Principles of Metamorphic Petrology. Cambridge University Press
• Shelley D (1992): Igneous and Metamorphic Rocks under the Microscope: Classification, textures, microstructures and mineral preferred orientation
• Cox et al. (1979): The Interpretation of Igneous Rocks, George Allen and Unwin, London.

Photo
frammentivetrosiignimbrite(2).jpg

Y-shaped glass gragment in a Ignimbrite. PPL image, 10x (Field of view = 2mm)
frammentivetrosiignimbrite(3).jpg

Glass gragments in a Ignimbrite. PPL image, 10x (Field of view = 2mm)
frammentivetrosiignimbrite(4).jpg

Glass gragments in a Ignimbrite. PPL image, 10x (Field of view = 2mm)
frammentivetrosiignimbrite(5).jpg

Glass gragments in a Ignimbrite. PPL image, 10x (Field of view = 2mm)
shard2017(1).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(2).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(3).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(4).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(5).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(6).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(7).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(8).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(9).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(10).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(11).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(12).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)
shard2017(13).jpg

Glass gragments ( C- and Y-shaped) in a ignimbrite from S.Pietro island, Sardinia, Italy. PPL image, 10x (Field of view = 2mm)