Gaas, April Shayne S.
BSCE- - 2Q
Geology for Civil Engineering
10/04/2023
SEATWORK 2
1. Why are minerals considered economically important? 10 pts.
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Minerals are considered economically important because they are used in a wide range of
applications related to construction, manufacturing, agriculture, and energy supply.
2. Identify the different rock forming minerals. 20 pts.
Here are some common rock-forming minerals:
● Feldspar
● Quartz
● Amphiboles
● Micas
● Olivine
● Calcite
● Pyroxenes
● Garnet
3. What are the physical properties of minerals? Describe each briefly. 40 pts.
Here are some of the common physical properties of minerals:
1. Hardness: This refers to the ability of a mineral to resist scratching.
2. Color: Color is one of the most noticeable properties of minerals, but it is not always a reliable
characteristic for identification.
3. Cleavage and Fracture: Cleavage refers to the way a mineral breaks along flat surfaces,
whereas fracture refers to the way a mineral breaks along irregular or uneven surfaces
4. Luster: Luster refers to the way a mineral reflects light. It can be described as metallic,
non-metallic, or sub-metallic
5. Streak: Streak refers to the color of a mineral’s powder when it is scraped across an unglazed
porcelain plate
6. Density: Density is the mass per unit volume of a mineral. It can provide information about the
composition and chemical structure of a mineral
7. Crystal form: Crystal form refers to the external shape of a mineral’s crystals
8. Magnetism: Some minerals, such as magnetite, exhibit magnetic properties and are attracted to
magnets
9. Optical properties: Some minerals exhibit optical properties, such as double refraction or
fluorescence
10. Transparency and opacity: Transparency refers to the ability of a mineral to transmit light, while
opacity refers to the inability of a mineral to transmit light
4. Identify and describe the three main types of rocks. 15 points.
Here are the three main types of rocks: igneous, sedimentary, and metamorphic.
1. Igneous Rocks
- These rocks form when molten rock (magma or lava) cools and solidifies.
2. Sedimentary Rocks
- Sedimentary rocks originate when particles settle out of water or air, or by precipitation of
minerals from water.
3. Metamorphic Rocks
- Metamorphic rocks result when existing rocks are changed by heat, pressure, or reactive fluids,
such as hot, mineral-laden water.
5. Identify and describe the rock cycle processes. 15 points.
Here are the key processes involved in the rock cycle:
1. Weathering: This is the process of breaking down rocks into smaller particles without any
transporting agents at play.
2. Erosion and Transport: Erosion is the natural process of breaking down rocks into sand-like
particles. These particles are then transported by natural forces like water, wind, and ice.
3. Deposition of Sediment: The eroded material is deposited in new locations, forming layers of
sediment.
4. Burial and Compaction: Over time, additional layers of sediment accumulate on top, causing
the lower layers to compact and harden into sedimentary rock.
5. Crystallization of Magma: When rocks are subjected to high temperatures, they melt into
magma. As the magma cools, it solidifies and crystallizes to form igneous rock.
6. Melting: Rocks can be melted again by Earth’s internal heat to form magma.
7. Uplift: Tectonic forces can push rocks back up to the surface.
8. Deformation and Metamorphism: When rocks are subjected to high pressures or temperatures,
they can be transformed into metamorphic rocks.