Cauliflower silicified geodes within Slunfeh Formation of
upper cretaceous were described. Mid-range infrared spectroscopy
FTIR was used for determination of mineral composition of these
geodes. Polarized light microscope was used for the study of
thin
sections taken from inner parts of geodes in order to determine their
crystal habits. The results showed that geodes of studied formation
consists of silicon in form of amorphous to cryptocrystalline opal,
chalcedony of micro-crystalline fibrous radial structure, hexagonal
prismatic quartz, radial quartz, zoned quartz and mosaic quartz.
Tripoli in the studied area is a porous, friable and lightweight siliceous
sedimentary rock composed mainly of microcrystalline quartz, and were found
to be resulting from silicification of limestone, and consists of microcrystalline
quartz and im
purities of calcite and halite; the silica ratio ranged between
63.01 – 96.75 % .
