Colloids and Marble

 Marble belongs to the types of rock whose forms waken strong associations with doughy-gelatenous consistencies.  Samples of it can give the impression, that its metamorphosis and deformations occurred in a malleable- to half-solidified condition

According to present-day conceptions, marbles are limestone sedimentary rocks which were slowly metamorphosed under high pressure, water content and elevated temperature in a solid condition.  Their starting material is thus considered to be a hard "finished" limestone such as we find today, which through regional metamorphosis (sinking down in zones with high pressure and increased temperature) or through contact metamorphosis (being near or contacting rising magma) were transformed to marble.

If one allows the forms of certain marbles to work on one, however, then one can come to doubt that slow, pseudo-plastic deformation in a hardened condition, or softening through heat, could have brought them about.  One rather has the impression that they were, at a certain period, half-solidified or firmly-gelled, and then deformed or stretched, and that, at the some time, a lighter-colored, more fluid portion was pressed out into the fractures, resulting in a fine network with flowing forms.

The pictures in the left-hand column below show, how marble-like structures could have originated:  in a half-solidified gel a diferently-colored colloidal fluid was introduced.  The right-hand column, for comparison, shows photos of actual marble from various regions.

On the left: Experiments with gel (agar)                                   Marble, Italy

kopie_von_04_kolloide_und_marmore_01.jpg kopie_von_04_kolloide_und_marmore_02.jpg
kopie_von_04_kolloide_und_marmore_03.jpg kopie_von_04_kolloide_und_marmore_04_1.jpg
kopie_von_04_kolloide_und_marmore_05.jpg kopie_von_04_kolloide_und_marmore_06.jpg
On the left: Experiments with gel (agar)kopie_von_04_kolloide_und_marmore_07.jpg Marble, Albania
kopie_von_04_kolloide_und_marmore_08.jpg
 
kopie_von_04_kolloide_und_marmore_09.jpg
Marble, Spainkopie_von_04_kolloide_und_marmore_10.jpg
 
kopie_von_04_kolloide_und_marmore_11.jpg
Dolomite marble, Norwaykopie_von_04_kolloide_und_marmore_12.jpg
 
kopie_von_04_kolloide_und_marmore_13.jpg
Marble, Greecekopie_von_04_kolloide_und_marmore_14.jpg
 
kopie_von_04_kolloide_und_marmore_15.jpg
Marble, Italykopie_von_04_kolloide_und_marmore_16.jpg

It should be added, that these colloidal experiments were done with very simple techniques.  With technical means, the entire range of marble morphology can be reproduced using colloids, which is actually done in the manufacture of artificial decorative rock.

In summary, one obtains the impression from the photos shown of marble, that during their metamorphosis they must have contained a large prcentage of water.