1

1

2

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2

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3

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2

4

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3

Feldspar.

Silicon.

Calcite.

Quartz.

Halite.

Hematite.

Biotite or biotite mica.

galena.

0.006 cm to 0.2 cm

B is calcite and A is bioclastic or organic. A is made mostly of calcite or cemented shells and B is made mostly of clay sized sediments, or B is made of clay, but not of calcite or cemented shells.

Cementing of shell fragments, direct chemical precipitation, or direct biologic or organic precipitation.

Layer A is shinier or brighter, is easier to carve because it is softer, and has a more uniform composition.

Clay.

1- Rock can be heated by contact with magma or lava.
2- Rock can be heated or compacted during mountain building or deep burial.
3- Rocks can be impacted by a meteor.
4- Rocks can be put under pressure in fault movement.

1- Biotite.
2- Quartz.
3- Amphibole.

the rocks that would form from the molten material would be igneous with the composition determined by the composition of the meteorite and bedrock impacted and melted. the textures of these igneous rocks would vary form glassy and/or vesicular at top, to fine texture, to coarse texture as depth and cooling time increased.

the type of rock that would form is metamorphic

The angular rock fragments could have fallen into a water body and compacted and cemented to form a breccia, if the sediments were carried by erosional agents for a considerable distance and rounded before being compacted and cemented, then the rock type would be conglomerate.

The crater formed in Devonian period of the Paleozoic Era of the Phanerozoic Eon.

The smooth sides or surface could be crystal faces that formed when the mineral formed, or the sides could be cleavage sides formed the mineral sample was broken. one way to tell which way the sides were formed is to break the sample and compare the geometry of the sides with the original sample. if the geometry is the same, then the original sides were likely to have been formed by breaking. Another way to determine the difference would be to melt the sample and let it cool very slowly in an open area so that its crystal surface would form. and then again compare the geometry with the original sample.

If the density of the two samples were determined, you could distinguish graphite from hematite by making reference to mineral tables. the streak of graphite is black and the streak of hematite is red. graphite has a greasy feel and hematite does not.

-Rock A–Shale.
-Rock B–gneiss.
-Rock C–granite

Heat and pressure when the rock is buried deep underground and plate collisions mountain building.

Granite, because granite is composed mainly of quartz and feldspar that are resistant to abrasion because their hardness (7and 6 respectively), while marble is made of calcite, which is softer (hardness of 3)

a) Calcite and Quartz.
b) Heat and Pressure.

The cross-section below shows a portion of the Earth’s crust where letters A, B, C, and D are rock units.

Igneous rock B was formed after rock layer D was deposited but before rock layer A was deposited. The dashed line symbol represents contact metamorphism zone. This symbol in red is the contact metamorphism zone where rocks underwent contact metamorphism when igneous rock B was molten.

There is no contact metamorphism zone in rock layer A since it was deposited after rock layer B was formed.

Rock-C was formed before both B and A (the oldest).

– Rock A is a mixture of rounded rock fragments of different sizes connected together.
(OR)
– Rock A is a horizontal layer.

1- Graphite is used in Lithium-Ion Batteries, which have a lithium cathode and a graphite anode.
2- used in writing because “Lead” pencil cores are made of a mixture of clay and graphite.

Diamond and graphite are made entirely out of carbon, The differing properties of graphite and diamond arise from their distinct crystal structures. In a diamond, the carbon atoms are arranged tetrahedrally, Because of its tetrahedral structure, diamond also shows a great resistance to compression. The hardness of a crystal is measured on a scale, devised by Friederich Mohs, which ranks compounds according to their ability to scratch one another. The carbon atoms in graphite are also arranged in an infinite array, but they are layered. These atoms have two types of interactions with one another. Unlike diamond, graphite can be used as a lubricant or in pencils because the layers cleave readily. It is soft and slippery, and its hardness is less than one on the Mohs scale.

Diamond has a hardness of 10 while graphite has a hardness of 1-2 based on the Moh’s scale. Graphite is characterized by steel gray to black in color, with a metallic, and sometimes earthy luster.