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Rocks can range from the ordinary stones in your background to beautiful minerals with multi-colored facets. You might be wondering what rocks are made of and how they are formed. Especially if you’re a Jurassic Park fan, you might also question if they contain DNA.
Rocks do not have their own DNA. However, some kinds of rocks can sometimes contain the DNA of other organisms. New research has found indicators of ancient DNA in fossils of dinosaur matter. Scientists have also found traces of the building blocks of DNA in meteorites.
In this article, we’ll cover everything there is to know about rocks and what they are made of. We’ll also explore how fossils are formed and how they can sometimes contain traces of ancient DNA. Lastly, we’ll take a look at meteorites and how new research shows evidence of the base of DNA.
If you are interested in checking out the best books about rock and minerals identification you can find them by clicking here (Amazon link).
What is DNA?
DNA is the acronym for deoxyribonucleic acid. It is made of the following 4 chemicals:
- Adenine
- Guanine
- Cytosine
- Thymine
Simply speaking, it is the genetic material of living things like plants, animals, and humans. Each cell of the organism contains the information of the DNA.
What Are Rocks Made Of?
There are 3 different kinds of rocks:
- Igneous rocks
Usually found in the Earth’s crust and around volcanoes. They are formed by volcanic processes like lava flow and the solidification of magma. You can also find them on the ocean floor. Common kinds of igneous rock include granite and basalt.
- Sedimentary rocks
Made from smaller particles of other rocks. Sometimes this also includes particles from animals or plants. The particles are pushed together by pressure in bodies of water like oceans, rivers, or lakes.
Common kinds of sedimentary rock include sandstone, mudstone, and limestone. Fossils are also commonly found in sedimentary rock.
- Metamorphic rocks
Originally sedimentary or igneous rocks. They transformed into a new rock formation due to pressure, heat, or fluid. This transformative process can happen near volcanoes, hot springs, or within the tectonic plates of the Earth. Common forms of metamorphic rock include marble, quartzite, and gneiss.
Each of the rocks is formed from different geological processes, which result in a collection of minerals. These minerals form what we commonly refer to as rocks.
Do Minerals Have DNA?
Rocks are made up of collections of minerals and minerals themselves are formed from a collection of different elements. They do not have any DNA in their structure.
Minerals are usually made up of one or more of the following elements:
- Oxygen
- Silicon
- Aluminum
- Iron
- Calcium
- Potassium
- Magnesium
- Sodium
Mineral Rock Types
Within the categories of rocks, there are sub-categories of mineral types.
The following table shows the common mineral rock types and examples of each kind.
| Mineral Group | Example |
|---|---|
| Sulfides | Pyrite |
| Halides | Fluorite |
| Oxides | Hematite |
| Carbonates | Dolomite |
| Sulfates | Gypsum |
| Phosphates | Apatite |
| Silicates | Quartz |
| Organics | Amber |
- Sulfides are usually made of sulfur and some kind of metal. These metals are commonly lead iron or mercury. This mineral group has a distinctive shiny and metallic appearance.
- Halides are usually made of the following elements: fluorine, iodine, bromine, and chlorine. Halides are symmetrical and can dissolve in water. A common example is rock salt.
- Oxides are made from a combination of metals with hydroxyl, water, or oxygen. This is a variable group of minerals with many different textures and appearances.
- Carbonates are a combination of carbon trioxide and other metallic elements. They are usually transparent and pale in appearance.
- Sulfates are made from the compound sulfate, combined with other metallic elements. These minerals are soft in texture and have a transparent color.
- Phosphates are composed of phosphate compounds with other metals. They are small clumps of crystals and easily broken.
- Silicates contain both silicon and oxygen. These minerals are variable and there are many different kinds in this category. Usually, these minerals are lightweight and are not transparent.
- Organics are distinct from other minerals. Their chemical structure includes hydrocarbons. Some geologists do not consider them to be true minerals.
TIP: Knowing the difference between rocks, minerals, and crystal is often more difficult than it looks. That’s why I decided to write the ultimate guide on this topic. Feel free to read it here:
Rock, Mineral, or Crystal? What’s the Difference?
Do Crystals Have DNA?
Crystals are a form of minerals. Both minerals and gems can be crystals, which is due to the arrangement of the elements of the mineral. They form recurring patterns of atoms which create crystalline properties and appearance.
Crystals often contain the elements of silica or calcium. They do not have DNA.
Do Fossils Have DNA?
Fossils are remnants of organisms that have integrated into sedimentary rock. Some of these fossils contain ancient DNA, which dates back up to a million years ago.
How Do Fossils Form?
Fossils form from the following processes:
- Carbonization
During the carbonization process, organic matter like leaves or fish is subjected to heat and pressure underneath the sediment.
This pressure releases hydrogen and oxygen, with only carbon remaining. This forms a fossil with a carbon imprint of the original organism, but no organic material or DNA.
- Petrification
Fossils formed from petrification are made when an organism’s bones become enclosed in sedimentary rock.
This happens when water enters the sediment and organic remains, forming crystals that harden the structure into a rock.
- Replacement
The replacement process happens when minerals found in water replace the minerals that dissolve as the organic material decomposes. This can form a cast in sedimentary rock.
This fun and interactive video illustrate how fossils are formed:
TIP: If you are interested in this topic, I wrote comprehensive articles about the main differences between petrification and fossilization. Check out this article here:
The Difference Between Fossilization and Petrification
Is DNA Found in Fossils?
For many years, scientists believed that the fossilization process destroyed all organic material and its associated DNA.
However, a 2005 study of bones of a Tyrannosaurus rex found that they contained soft tissue from the dinosaur. Iron in the dinosaur’s body allowed it to preserve this organic material for millions of years. The scientists identified proteins in this soft tissue, with the possibility of DNA coding.
Researchers in 2020 also found chemical compounds that were structurally similar to DNA in the cartilage of a duck-billed dinosaur. These compounds have not yet been confirmed as DNA, but they respond similarly.
This suggests that some fossils may contain trace amounts of ancient DNA. However, this is an evolving area of study and research.
Do Meteorites Have DNA?
Meteorites are rocks from space that come to Earth. They are called meteorites when they hit the ground of our planet.
For many years, scientists have discovered genetic material on meteorites. However, they argued that it could be cross-contamination from other matter found on Earth. Therefore, they contested that the DNA was from our planet and not from space.
However, a study from 2011 found a meteorite that contained chemicals that form DNA. These nucleic acids form the basis of the genetic material. This finding suggests that there could be life on other planets.
While the meteorites do not have their own DNA, they are shown to potentially carry the genetic material from places other than Earth.
Related Questions about Rock’s DNA
When writing about the DNA of rocks, the question about cells or feelings comes to my mind right away. And I don’t think I’m the only one with similar questions. So you can find interesting related questions below:
Do Rocks Have Living Cells?
No rock is made up of living cells. On the other hand, on the surface of all kinds of rocks, minerals, or crystals, there are various living organisms, which are formed by living cells.
Are Rocks Alive?
No rock is alive. However, some rocks are of organic origin. This means that they were formed primarily by the process of fossilization or petrification from living organisms.
Do Rocks Have Feelings?
Rocks, minerals, or crystals don’t have brain or sense organs so they are not able to feel anything. So that is the reason why they don’t have any feelings.
BTW: Do you want to know more about rock and mineral identification? The books listed below are the best ones you can find on the internet (Amazon links):
- Smithsonian Handbooks: Rocks & Minerals
- Gemstone & Crystal Properties (Quick Study Home)
- Ultimate Explorer Field Guide: Rocks and Minerals (National Geographic Kids)
Summary
Rocks do not have their own DNA. Rocks are made of collections of different minerals. These structures form from different processes in the Earth, which usually involve pressure and/or heat. Minerals and crystals are made of different combinations of elements. They also do not have DNA.
Fossils are collections of organic material that have been embedded in sedimentary rock. Scientists are now discovering that some fossils may carry DNA from the original organisms.
Lastly, scientists have also learned that meteorites can carry DNA from outer space.
So, while the rocks themselves do not have their own genetic material, they can carry it from other organisms.
TIP: If you happen to feel disappointed with the answer to the question of whether the rocks have DNA, I have a suggestion for you. Even without DNA, the rocks are still amazing, and imagine that you can easily find many of them around your backyard:
12 Gemstones You Can Find in Your Backyard Right Now