kimberlite, also called blue ground, a dark-coloured, heavy, often altered and brecciated (fragmented), intrusive igneous rock that contains diamonds in its rock matrix. It has a porphyritic texture, with large, often rounded crystals (phenocrysts) surrounded by a fine-grained matrix (groundmass).
How do you identify a kimberlite rock?
Kimberlites are very diverse, but generally have distinct trace mineralogy. The only way to absolutely identify one is by thin section and chemistry. And finding a kimberlite that contains diamonds is even rarer – most do not.
How much is a kimberlite worth?
Kimberlites form this region do yield beautiful diamonds which mostly range from very small to a maximum of 3 carats. Customers have found 1/4 carat to 1/2 carat blue diamonds and yellow & clear diamonds between 1/4 and 2 carats within our specimens worth $1,500-$4,000.
What gems are found in kimberlite?
Garnet, chromite, ilmenite, chromium diopside, and olivine occur in kimberlites in significantly higher quantities than diamonds. As kimberlite indicator minerals, they are used for diamond prospecting, as well as for the primary assessment of whether a target kimberlite is diamond-bearing or not.
How do I know if my kimberlite has diamonds?
Finding large concentrations of G10 garnet can be a good indication of a diamondiferous kimberlite. On the Mohs hardness scale, garnet has a hardness of 8, compared with diamonds, which have a hardness of 10.
How can you tell if a rock is a diamond?
The only hardness test that will identify a diamond is scratching corundum. Corundum, which includes all rubys and sapphires, is 9 on the hardiness scale. If your suspected diamond crystal can scratch corundum, then there is a good chance that you found a diamond. But NO OTHER HARDNESS TEST will identify a diamond.
What colors is kimberlite?
kimberlite, also called blue ground, a dark-coloured, heavy, often altered and brecciated (fragmented), intrusive igneous rock that contains diamonds in its rock matrix. It has a porphyritic texture, with large, often rounded crystals (phenocrysts) surrounded by a fine-grained matrix (groundmass).
Where do you find kimberlite?
Generally speaking, kimberlites are found only in cratons, the oldest surviving areas of continental crust, which form the nuclei of continental landmasses and have remained virtually unchanged since their formation eons ago.
What does a diamond look like when it’s found?
Shape: Diamonds found at the Crater are typically smooth and well rounded. Their shape resembles a polished stone with smooth sides and rounded edges.
How do you extract diamonds from kimberlite?
The kimberlite is extracted in enormous quantities using huge trucks and giant steam shovels; the pipe is mined from the surface as an open pit. When it gets too deep, underground mining may begin. Because of the huge quantities of rock involved, the mining is highly mechanized.
How much are kimberlite diamonds worth?
Modeled prices ranged between US$129 and US$355 per ct for the diamond populations of the major kimberlite units making up the Star and Orion South kimberlites.
What type of soil do you find diamonds in?
Pipes of the minerals kimberlite and lamproite are often present in the Earth’s upper mantle, and they carry diamond crystals in their pipe “trails.” These minerals are resistant to weathering and are denser than quartz sand.
What to look for when finding diamonds?
Here are some tips to help you spot a real diamond:
- They do not look like the ads. Diamonds sold in stores are already cut and polished.
- Check for their natural shine. Diamonds are literally brilliant.
- Diamonds are rounded not edged.
- Check for translucency.
- Check for toughness.
Is kimberlite hard or soft?
Fresh kimberlite is hard and a dark blue green color and as it oxidizes it becomes much softer and changes to a yellow brown.
How do you separate a diamond from a rock?
The most common separation method is called dense media separation or DMS. A DMS plant also uses the principal that diamonds are heavier than most of the surrounding rocks and minerals. Most modern DMS plants utilize a hydrocyclone (or ‘cyclone’), which is essentially a large centrifuge.
In what type of rock are diamonds found?
Diamond is only formed at high pressures. It is found in kimberlite, an ultrabasic volcanic rock formed very deep in the Earth’s crust. The extreme pressures needed to form diamonds are only reached at depths greater than 150km.
What do raw diamonds look like in rocks?
Rough diamonds usually resemble lumps of pale colored glass. They often have an oily appearance and don’t sparkle. Very few rough diamonds are actually gem quality. Only those with the very palest colors, or are colorless will pass the test.
What do diamonds look like in the raw?
On most occasions, raw diamonds look like a collection of pale-colored glasses. You should not expect these stones to shine with their oily appearance since they are yet to be cut. Additionally, rough diamonds have a high gem quality, and only those that are very pale and colorless pass the test.
How do I identify my kimberlite pipe?
It will usually have noticeably different colored specs or spots within and surrounding the stone. These spots are crystals such as garnets and possibly diamonds. Once in hand, kimberlite should have a porphyritic texture, with large, rounded crystals surrounded by a fine-grained ground mass.
What is the shape of a kimberlite pipe?
Kimberlite Pipes. Carrot-shaped volcanic pipes rising from the upper mantle 100-300km beneath the crust. They are formed through the high-pressure eruption of kimberlite magma, which expands and breaks rock as it reaches the crust.
How do you dissolve a kimberlite?
Instead of crushing the kimberlite rock, the kimberlite can simply be soaked in water (with appropriate added salts), using the internal forces within the kimberlite to break it apart.
