Pumice Properties Kenya

Physical Properties

• Composed of highly micro vesicular glass pyroclastic with very thin, translucent bubble walls of extrusive igneous rock.
• Commonly, but not exclusively of silicic to intermediate composition but basaltic and other compositions are known.
• Commonly pale in color ranging from white, cream, blue or grey to green-brown or black.
• Is a common product of explosive eruptions (plinian and ignimbrite-forming) and commonly forms zones in upper parts of silicic lavas.
• Has a porosity of 64-85% by volume, floats on water possibly for years, until it is eventually waterlogged and sinks.
• Occurs in two main forms of vesicles, tubular and subspherical micro vesicles.

Chemical Properties Properties

• Chemical name: Amorphous Aluminum Silicate.
• Hardness (MOHS): 6
• pH: 7.2
• Radioactivity: none
• Loss on Ignition (LOI) : 5%
• Softening point: 900°C
• Water soluble substances: 0.15%
• Acid soluble substances: 2.9%
• Reactivity: Inert

Typical Chemical averages

• Silicon Dioxide- 76.2%
• Aluminum Oxide- 13.5%
• Ferric Oxide- 1.1%
• Ferrous Oxide- 0.1%
• Sodium Oxide- 1.6%
• Potassium Oxide- 1.8%
• Calcium Oxide- 0.8%
• Titanium Oxide- 0.2%
• Magnesium Oxide- 0.05%
• Water- <1.0%