Kimberlite rocks are generally dark green, blue, or purple in color. They are typically made up predominantly of olivine and may contain pyroxenes and carbonates, along with other accessory minerals.
The rocks tend to be fine-grained and can sometimes resemble clinkers. Kimberlite rocks are often formed in a distinctive cone shape and may contain phenocrysts of olivine, pyroxene, ilmenite and sometimes diamonds.
In some cases, bits of the colorful host rocks they were formed in may also be present. Kimberlite rocks are very resistant to weathering and are generally hard and compact.
How do you identify a kimberlite diamond?
Kimberlite diamonds are the hardest to identify because they are from a type of rock called kimberlite which can be found mainly in South Africa and other parts of the world. A diamond found in kimberlite rock has a special set of characteristics that help to identify it.
The color of kimberlite diamonds is usually a yellowy-brown or yellowish-green shade, and they are often smaller in size and not as transparent as other types of diamonds. Natural kimberlite diamonds feature a unique combination of inclusions that can only be seen under a microscope.
They may contain mineral olivine or a type of garnet called pyrope, both of which cannot be found in other forms of diamonds.
The most reliable way to identify a kimberlite diamond is to have it examined by a gemologist or diamond expert. They will use a specialized diamond testing device to determine if the stone is a kimberlite diamond.
Additionally, a gemologist will use a special type of ultraviolet light to help them identify the diamond’s authenticity.
What colors are kimberlite?
Kimberlite is a type of igneous rock that is composed of a variety of minerals and can come in a range of different colors. These colors can vary depending on the specific mineral components that are present.
Generally, kimberlite will be shades of green, blue, purple, and even white. It can sometimes have swirls of different colors that create a beautiful speckled effect. The minerals in kimberlite can also give it the appearance of black flecks of mica or olivine that are situated among the other colors.
Is kimberlite hard or soft?
Kimberlite is an igneous rock that is considered to be extremely hard and tough. On Mohs scale of hardness, kimberlite is rated at 5. 5 to 6. 5, which is among the harder rocks in the scale (with 10 being the hardest).
Its hardness is attributed to its composition, which is primarily consisting of olivine and phlogopite, along with other minerals. Kimberlite has a brittle quality, and tends to fracture with sharp edges, making it difficult to break.
It is also not malleable, and has a low flexibility when bent. This hardness and lack of malleability makes kimberlite hard and difficult to work with for many uses.
Is kimberlite Magnetic?
No, kimberlite is not magnetic. Kimberlite is an igneous rock composed mainly of olivine and phlogopite, which are both non-magnetic minerals. The rock itself does not have any magnetic properties. Kimberlite does occur in close association with magnetite, which is a magnetic mineral.
Magnetite can be from 1-5% of the total rock mass of kimberlite and its presence can influence magnetic signature readings.
Can you find gold in kimberlite?
In most cases, you cannot find gold in kimberlite. Kimberlite itself typically does not contain a large amount of gold. However, kimberlite is a type of igneous rock that is known to contain diamond and other valuable minerals, such as chromite and platinum.
It is also believed to contain significant amounts of other elements such as iron and phosphorous. For example, kimberlite often contains iron in the form of magnetite, which contains relatively high concentrations of gold in trace amounts.
What is more, kimberlite is sometimes found in proximity to other types of gold-bearing rocks and minerals. These rocks, such as granite or quartz, can contain gold particles that can have been transported by the kimberlite magma up to the surface.
Thus, while it is not common to find gold in kimberlite, it can sometimes be found in proximity to, or carried by, kimberlite magma.
What gem is often found in kimberlites?
The gem diamond is often found in kimberlites, which are an unusual and relatively rare rock formation that form during volcanic eruptions. Kimberlites are composed primarily of minerals such as olivine, phlogopite, and diopside, which are all fairly hard and resistant to weathering.
As the kimberlites form, they pick up diamonds from deeper parts of the earth and forcefully transmit them to the earth’s surface. Kimberlite eruptions are so powerful that the gemstones can be scattered miles away from the initial eruption site.
In addition to diamonds, kimberlites can also contain other valuable gems such as garnets, sapphires, and rubies.
What are the different types of kimberlite?
Kimberlite is an igneous rock found deep within the Earth’s crust. It is a type of peridotite and is believed to originate from the Earth’s upper mantle and function as a primary source of diamonds. There are two main types of kimberlite: hypabyssal and volcanic.
Hypabyssal kimberlite is the most common type. This type of kimberlite typically occurs in sills, dikes, and other structures within the Earth’s crust. It is made up of olivine, pyroxene, and sometime diamond, and tends to be fine grained.
Hypabyssal kimberlite typically has higher concentrations of diamonds than other types of kimberlite.
Volcanic kimberlite is a type of eruptive kimberlite and is a rare phenomenon. These eruptions usually occur at depths of 120-200km. The volcanoes are usually small and only active for a few thousand years before going extinct.
Volcanic kimberlite tends to be coarse grained and is usually composed of olivine, pyroxene, spinel, and diamond.
In addition to these two main types of kimberlite, there are hybrid types of kimbrelite as well. These types of kimberlite occur with a mix of eruptive and intrusive structures and is found in sites with a lower diamond content than hypabyssal kimberlite.
The hybrid types of kimberlite occur in cratons and are made up of olivine, pyroxene, and diamond.
All types of kimberlite tend to form in the Earth’s upper mantle, which is why it can be so difficult to locate and mine. Nonetheless, it is an important source of diamonds and is at the heart of many geologically fascinating areas.
Where can kimberlite rocks be found?
Kimberlite rocks are found in a number of countries around the world, most notably in Africa, Australia, Brazil, India, Russia, and the United States. They form deep underground as a molten rock and then travel quickly to Earth’s surface when the pressure of underground magma increases.
When they reach the surface, they cool quickly into the distinctive blue-green rock of diorite, peridotite, or eclogite. Kimberlites are responsible for some of the world’s most famous diamond deposits, which are found in countries such as South Africa, Australia, Canada, and Russia.
The best kimberlites to find in these countries are located in areas that have experienced volcanic eruption or have deeply weathered basement rocks, which are more likely to contain diamond deposits.
In the US, kimberlite-related diamonds can be found in several states, including Arkansas, Montana, Colorado, and Wyoming. Additionally, several meteoric impact sites scattered throughout the US contain kimberlite remnants in the form of Black Matrix or impact glass.
Where is kimberlite found in the US?
Kimberlite is an igneous rock, often containing diamonds, that is found in a type of volcanic pipe known as a kimberlite pipe. In the United States, kimberlite is found most commonly in Arkansas and in the Colorado Plateau region which covers parts of Arizona, Colorado, New Mexico, Utah, and Wyoming.
The most famous U. S. kimberlite deposits are located in the Pike County area of Arkansas, which is known as the Arkansas Diamond Province. Significant kimberlite deposits have also been found in northeastern Arizona, southeastern Colorado, northern New Mexico, western Utah, and southern Wyoming.
Recently, additional kimberlite deposits have been found in Oregon, Idaho, and northern Tennessee.
Why are kimberlites only found in certain areas?
Kimberlites form when deep magma pushes through the earth’s crust in a process called “volcanic eruptions”. They contain high concentrations of diamonds and other minerals, which is why they are sought after by mining companies.
Kimberlites are only found in certain areas because the process of eruption happens when several conditions align. These conditions depend on the type of crust and magma present, the geothermal gradient, and other geological features that control the rate of magma intrusion.
When the magma rises fast enough, the underground pressure is released, causing an explosion and resulting in a kimberlite causing group.
These kimberlites are usually found in the oldest and most stable parts of the continents; the stable regions have the correct mix of magma and the Earth’s crust that allows for the magma to burst through.
In addition, the most stable areas of the continents are generally found near the equator, where tectonic plates move at a slower and more uniform rate. Hence, kimberlites are found mostly in areas near the equator or in ancient, stable regions.
Where is the place to find diamonds in USA?
The only place in the United States that you can find and mine diamonds is in Arkansas. The Crater of Diamonds State Park in Murfreesboro, Arkansas is the world’s only diamond-producing site open to the public.
Here, visitors can search a 37 1/2-acre field that is the eroded surface of a volcanic crater. Additionally, the Park has an interpretive center, amphitheater, and a campground. Visitors can even keep the diamonds and other gems they find.
This park has yielded more than 75,500 diamonds since it began and has the reputation of being the 8th largest diamond-producing site in the world.
Why are diamonds not found everywhere on Earth?
Diamonds are not found everywhere on Earth because they are created under specific geological circumstances, which only occur in a few parts of the world. Over millions of years, diamonds are formed in the Earth’s mantle – a layer of hot rock located below the crust.
The temperature and pressure of this environment must be equal to or greater than those found 100 miles below the surface of the Earth and temperatures must reach, at least, 752 degrees Fahrenheit. Additionally, in order to form a diamond, there must be carbon-rich fluids in the Earth’s mantle which deliver carbon atoms to form diamond crystals.
The presence of these unique conditions allows diamonds to form over long periods of time at depths of around 150km below the surface of the Earth. As a result, the majority of diamonds that are mined are found in a few select areas of the world, such as in Russia, Canada, South Africa, Botswana, and The Democratic Republic of Congo.
So, due to their specific formation requirements, diamonds are not found everywhere on Earth.
Why are diamonds only found in regions of very old continental crust?
Diamonds are only found naturally in regions of very old continental crust because these areas are typically very stable and have commonly experienced episodes of very high heat and pressure for a significant period of time.
These conditions and conditions in the Earth can sometimes be so extreme that they cause carbon in the Earth’s mantle to break down, packaging the carbon into tiny diamond crystals. In order for these conditions and conditions in the Earth to exist, the crust must be very old and have been very stable throughout the periods of high pressure and temperature.
This often occurs in the form of cratons, or areas of very old continental crust that have been stable, or at least very consistently stable, since the earliest days of the Earth’s formation, allowing for no movement that would disrupt the intense pressure and heat necessary to create diamonds.
How much is kimberlite worth?
This can be a complicated question to answer since the value of kimberlite varies depending on many factors. One of the main components in evaluating the worth of kimberlite is its diamond content. If the kimberlite contains diamonds, it is potentially worth more and can range from approximately $50 – $200 USD per tonne in industrial-grade diamonds and could be higher depending on the quality and size of the diamonds.
When evaluating the worth of kimberlite for other components, factors like the amount, grade and type of metal, the geology of the ore and the overall in-situ value of the deposit will have to be considered.
Typically, kimberlites are considered “uneconomic” unless there is a greater than 1g/tonne gold grade, or 2% copper or 1% nickel or higher. Furthermore, if the kimberlites are located in a mining friendly jurisdiction and all other mining requirements can be met, the value of the ore in the ground can also be considered.
Lastly, the depth of the kimberlite, type of host rocks and other factors that are associated with the mining process come into play when evaluating the worth of kimberlite. On average, depending on the other factors mentioned, kimberlite can sell between $1 and $20 per tonne.
