Type of Rock Sedimentary Rock

Type of Rock Sedimentary Rock: Gypsum

Rock Identification Gypsum rock have inconsistent jiggered rough appearance. Accumulation of gypsum mineral create gypsum rock and naturally gypsum rock are white in colour. However, different foreign substances that combined t to form this rock may give a various different colours to the gypsum.
Description of gypsum:
Type Name Cleavage Colour Lustre Hardness Specific Gravity
M456 Gypsum Have cleavage White or grey in colour Vitreous to silky 2 2.33
Characteristics Features and Physical Properties Soft mineral and considerably less in weight mineral that have quite a fast rate of solubility in water. Gypsum is originally white or grey in colour but in some occurrences, its colour of appearance can also become green, pink, and brown as a result of addition of foreign substances. The crystal of gypsum have good flexibility but once they are stretched to one certain length ,they will not return to original shape.
Mode of Formation and Occurrence Rock gypsum will formed when concentrated solutions like seawater evaporated. Hence gypsum rock are abundant at places with high evaporation rate such as at desert lakes and marine region. At desert, formation of gypsum crystals is called as “desert rose” formation as it imitating the appearance of flower’s petals.
Similar rocks and minerals Gypsum is sometimes confused with anhydrite. Both gypsum and anhydrite share an approximate appearance. Studies shown that they are commonly found in the same colour which is white colour.
Gypsum and bassanite have approximate the same chemical composition. The white coloured crystal and bassanite contain hydrous calcium sulphate, however, gypsum(CaSO4·2H2O) contains more water compare to bassanite (CaSO4·0.5H2O)
Gypsum is widely used manufacture of wallboard, cement, plaster of Paris, soil repairing, and a hardening agent in cement. Gypsum is highly important in construction work is ra due to its nature-friendly properties. Study shown that gypsum construction products have enhance properties thermal conductivity.

Type of Rock Sedimentary rock: Shale

Rock Identification The most abundant sedimentary rock on Earth is this rock. It have laminated appearance and usually formed in sheets. Shale is also another type of fine-grained rock and have silt and clay sized particles. Shale consists of clay, minerals and large amount of quartz. This rock also have small numbers of carbonates, and organic matters

Explanation of quartz:
Type Name Cleavage Colour Lustre Hardness Specific Gravity
M286 Quartz Indistinct No colour Vitreous 7 2.65
Characteristics Features and Physical Properties Shale are fragile. It easily tear apart into layers. The layers are thin and usually will be parallel to surface. Other properties of shale included of being in plastic state property and permeability. Shale have very tiny pores known as nanopores within its structure. Shale will be darker in colour and this colour intensity is influenced by the of organic matter inside. Limonite will turn shale rock to become and purple colour.
Mode of Formation and Occurrence Shale forms as a result of compaction and cementation of eroded materials from older rocks. Compaction and cementation of clay and silicates will eventually form shale. Shales are usually found at places with very slow flowing water such as lakes, river deltas, and sedimentary basins.

Similar rocks and minerals Most of the time, shale are being confused with slate. Both stone have very little difference in terms of appearance and one cannot directly distinguish these two type of rocks by just visually examined it. Slate is metamorphic rock that formed from shale that exposed to pressure and heat.

In terms of mineral similarity, shale can be related to schist. Schist is a metamorphic rock that formed through metamorphosis process. Study revealed that schist parent rock was shale which mean shale rock that undergo metamorphosis will end up become schist. Since schist was once shale rock, their mineral composition is more or less the same.

Shale are crucial substance in the industry that related to ceramics. Shale have become the main material to manufacture products like tile ,brick and pottery. Organic-rich shales known as oil shales that contain kerogen are currently being study to turn it into beneficial source for liquid petroleum