Scottish Gemmological Association Talk – SMLC members Welcome
Wednesday, October 30th, 6.30 for 7.00pm
(please note early start)
Marco Campos Venuti, speaking on Agates – ¨The Big Band Theory¨
An insight in shape modelling of banded agates.
About the talk: F irst we have to understand that natural silica is not a mineral, but a polymer. This is a completely new world with a different physics than classical mineralogy. The main differences are the slow passage from liquid to solid (in crystals, atoms are in full solution and one second after, they are solidly bound to a crystal lattice) and that solidification is reversible. The processes are water driven at room temperature, so we are in a pedogenetic environment, a few meters inside the soils.
We usually think crystals are grown in millions of years, but they are subjected to very slow chemical and physical variations. To the contrary, in soils every rain and every change in season strongly influences the formation of the agate. And they are formed in a few years!!
With our study we opened a window in the agates formation that enlightens much information on the past geological history.