Marble. Cut surface of marble,a type of metamor- phic rock derived from limestone. Pure marble con- sists only of the minerals calcite and dolomite,and is white. The orange streaks here are caused by impurities of other minerals. Marble is formed when limestone is subjected to intense heat and pressure,which cause the calcite in the rock to recrystallize into coarse,interlocking grains. This rock has been subjected to a second form of metamorphism that has broken up the marble into angular fragments (breccia) cemented together by finer material. Marble,both raw and polished,is widely used in building. This sample is from Portugal. Magnification x0.25 at 35mm size | |
Licence : | Droits gérés |
Crédit: | Science Photo Library / Bernard, George |
Taille de l’image : | 5176 px × 3484 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |