Any idea what are these circular rock marks?

Asked by: Chad Cooper

How can you tell what kind of rock you have?

Possibilities include:

1. Your state geological survey.
2. A natural science museum.
3. A college or university with a geology department.
4. A rockshop.
5. Members of a local Gem & Mineral club or Rockhunting club (many hobbyists are experts at identification)
6. Vendors at a Gem & Mineral show.

How do sedimentary rocks form?

Clastic sedimentary rocks are made up of pieces (clasts) of pre-existing rocks. Pieces of rock are loosened by weathering, then transported to some basin or depression where sediment is trapped. If the sediment is buried deeply, it becomes compacted and cemented, forming sedimentary rock.

How does erosion affect sedimentary rocks?

Erosion and weathering transform boulders and even mountains into sediments, such as sand or mud. Dissolution is a form of weathering—chemical weathering. With this process, water that is slightly acidic slowly wears away stone. These three processes create the raw materials for new, sedimentary rocks.

What role does water play in the formation of sedimentary rocks?

Water plays a role in the formation of most sedimentary rock. It is one of the main agents involved in creating the minerals in chemical sedimentary rock. It also is a weathering and erosion agent, producing the grains that become detrital sedimentary rock.

Are there any rocks worth money?

Jadeite is the most expensive mineral, or rock, in the world at this time. Price per carat for this costly gem is three million dollars a carat! Jadeite’s beauty and rarity are what makes this rock so pricey. With stones coming in a variety of colors, each stone is unique, but still very much looks like Jadeite.

Is there an app that can identify rocks?

The KamenCheck and the RockCheck apps are available for free on the Google play store and are adapted for use on Android devices (soon also planned for iOS).

What is formation of igneous rocks due to hardening of magma?

Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust. All magma develops underground, in the lower crust or upper mantle, because of the intense heat there.

What are the main characteristics of sedimentary rocks Class 7?

Characteristics of sedimentary rocks are-



They are found on Earth in a large amount,about 75%. They are formed due to deposition of sediments,so they are soft. The sediments are from older rocks,plants,animals,etc… They are generally non shiny and non crystalline.

How extrusive igneous rocks are formed?

Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth’s surface. These are the rocks that form at erupting volcanoes and oozing fissures.

How does climate change affect weathering and erosion and deposition?

Climate changes, such as more frequent and intense rain events, can increase erosion and result in greater amounts of sediment washing into rivers, lakes and streams. More frequent and intense rain events, can increase sediment loading from stormwater runoff.

WHY WILL activities that lead to sedimentation affect the quality of freshwater in lakes?

Sediments in suspension can have a significant impact on the water quality of a waterway because sediments decrease water clarity, which reduces visibility.

What is the impact of erosion and sedimentation on aquatic resources?

The environmental impacts of sedimentation include the following: loss of important or sensitive aquatic habitat, decrease in fishery resources, loss of recreation attributes, loss of coral reef communities, human health concerns, changes in fish migration, increases in erosion, loss of wetlands, nutrient balance

What kind of rock is worth a lot of money?

Granite is much harder than gold, but it’s far less valuable than gold.

What rocks contain gold?

Gold is also found at times in chalcopyrite, galena and arsenopyrite and stibnite, but not as a rule in such large amounts as may be found in pyrite. Other minerals, like sphalerite, pyrrhotite, magnetite and hematite sometimes carry small amounts of gold as well. Gold also occurs as tellurides such as calaverite.

What is the most valuable rock?

Top 15 Most Expensive Gemstones In The World

• Blue Diamond – $3.93 million per carat. Blue diamond. …
• Jadeite – $3 million per carat. …
• Pink Diamond – $1.19 million per carat. …
• Red Diamond – $1,000,000 per carat. …
• Emerald – $305,000 per carat. …
• Taaffeite – $35,000 per carat. …
• Serendibite – $18,000 per carat. …
• Diamond – $15,000 per carat.

How do you tell if a rock is igneous or metamorphic?

Look for crystals in igneous rocks. Examples of igneous rocks are gabbro, granite, pumice and obsidian. Metamorphic rocks are rocks that have become changed by intense heat or pressure while forming. One way to tell if a rock sample is metamorphic is to see if the crystals within it are arranged in bands.

How do you identify if a rock is igneous sedimentary or metamorphic?

(B) Igneous rock is a form of crystal, while sedimentary rock is formed by layers building up on the surface of the Earth, and metamorphic rock is formed from intense heat and pressure over time.

How can you identify a sedimentary rock?

Sedimentary rocks such as limestone or shale are hardened sediment with sandy or clay-like layers (strata). They are usually brown to gray in color and may have fossils and water or wind marks. Metamorphic rocks such as marble are tough, with straight or curved layers (foliation) of light and dark minerals.

What do igneous rocks look like?

Quote from video: And then solidifies igneous rocks may form from magma which is found inside the earth or lava which is molten rock on the surface of the earth. There are two major types of igneous rocks intrusive.

What do metamorphic rocks look like?

One is known as foliated metamorphic rocks, where the rock has many layers or bands to its texture. Some examples of this kind are slate and schist. Another kind of metamorphic rock is non-foliated, where the rock does not have layers or bands to its texture. Instead, it may have a smooth to grainy like appearance.