FMF - Friends of Minerals Forum, discussion and message board

[Kharv]

Anyone have experience with carbonado diamonds? Having a hard time finding someone to examine and certify. Density test checks out, I can not scratch it with a carbide scribe and I really tried multiple times pressing as hard as I could. From all the research I can find online the only thing it could be is carbonado, viewed under a microscope the structure matches.

[Herwig]

Diamond has a high affinity to grease.
Make a small flat object and put a blob of grease on it (butter should work fine too).
Make sure the upper surface of the grease is smooth.

Take your carbonado and put it on top of the grease. Next, hold the object upside down. The carbonado should stick to the grease. Clean your carbonado, so there is no more grease on it.

Next, put the "grease bearing object" underwater.
Take your carbonado and put it in the water, make sure it is completely wet all around
next, put the carbonado on top of the grease, just like you did the first time.
Again, the carbonado should stick to the grease.

Eventually do the above with a genuine diamond first, to get a feeling of what exactly needs to be done ...
Other materials, like quartz, will not stick to the grease, once they are wet on all sides; diamond will.

[Peter Lemkin]

Diamonds are rare. You didn't mention if you found it anywhere near where other diamonds have been found. The size of it [huge] alone would make me skeptical it was a diamond - but perhaps you have won nature's lottery.There are a few locations in Canada with diamond kimberlite pipes, but the largest are thumbnail size and even those are exceptionally rare! Canada is home to five important diamond mines. Ekati, Diavik and Gahcho Kué are located in Canada’s Northwest Territories. Renard and Victor are located in Québec and Ontario, respectively. The Victor mine is now closed, while the other four are active.

[alfredo]

Regular diamonds are rare, but carbonados are even more rare, being found almost exclusively in Brazil and the Central African Republic.

Most of the time, when people think they've found any sort of diamond, the hardness test was done wrong. (Not saying you did your hardness test wrong, but that's what happens in most "diamond finds".)

[Kharv]

Carbonado does not come from kimberlite it's origin is unknown yet most beleave they are born in space likely with a start explodes, if they are Infact from space they could quite possibly be alot more abundant then previously thought, when they are dirty on the ground they jest look like a ugly rock
. I'm skeptical as well but I also found a beautiful river polished boulder of jade 4 being used as a door stop at a doller store... I won't be surprised if it's not carbonado but I spoke with a guy selling some on 1stdb1 and mine is very similar to his witch are verified and he believes it to be 1. Thanks for your imput

[Kharv]

Ya I've exhausted all information I can find online, the inigma sold as a space diamond, if they are formed in space you could have one in your your yard , I truly tried with multiple carbide tipped bits and some fractured sapphire I have punched as hard as I can and after I clean the scratched area you can't tell I ever tried.. I did a density test as well and I also used a half dozen rocks from jade to quartz all same size and heated them and left them outside to see Wich retain heat and it stayed marm considerably longer as well when I brought them in it stayed cool considerably longer.. original thought opaque sapphire but to stricter magnified only resembles one thing I have found..

[Kharv]

Zoom2

[Kharv]

Zoom3

[Kharv]

Endv

[Kharv]

Thank you il try and post findings, never heard of these before much appreciated

[Peter Lemkin]

There are many good books just on natural diamonds. One is Ralf Tappert and
Michelle C. Tappert, Diamonds in Nature, A Guide to Rough Diamonds 2011, Springer ISBN 978-3-642-12571-3

You could always try burning it in a hot flame. Diamonds burn......

"Carbonados are another type of polycrystalline diamond. They have
smaller grain sizes and a higher porosity than framesites. Carbonados are
commonly black, dark grey, or brown due to the presence of numerous
small minerals lining the pore spaces (Fig. 2-56). Minerals associated with
carbonados include unusual phases such as florencite, xenotime, zircon,
and various native metals and alloys.51, 294, 300 No typical mantle miner-
als have been found associated with carbonados. Carbonados are unique
because their stable carbon isotope compositions are unusually light (δ13C:
-23 to -30‰) when compared to the stable carbon isotope compositions of
the other types of polycrystalline diamonds.150
The largest diamond mass ever found was a carbonado named Sergio,
which weighed 3,167 carats (~ 633 g). Carbonados are restricted to placer
deposits in eastern South America, mainly in the state of Bahia, Brazil; and
to the Central African Republic. In both areas, the carbonados are derived
from Mid-Proterozoic (1-1.5 billion year old) conglomerates that were de-
posited when South America and Africa were part of the same continuous
land mass. Radiometric age determinations indicate that the carbonados
crystallized long before the deposition of the conglomerates—between 2.6
and 3.8 billion years ago.217, 243
It is not completely understood how carbonados formed, but they
do not seem to be directly associated with kimberlites or other mantle-
derived rocks. It has been proposed that carbonados formed as a result of meteorite impacts on Earth that converted carbonaceous matter directly
into polycrystalline diamonds.163, 259 In a more controversial hypothesis,
carbonados represent actual fragments of a meteorite that impacted with
Earth.84, 103 In alternative models, the individual diamond crystallites of
carbonados formed in the Earth’s mantle, and they were welded together
by natural irradiation after being emplaced in the crust 144 or by the high
temperatures of the magmas that transported the crystallites to the Earth’s
surface.28"

[Kharv]

Thank you, when you say the burn what does that mean? If seen one come out of hot Coles and get dropped into water without damage, could have been fake but looked real

[Kharv]

You mean don't burn correct?

[Herwig]

Dear Karv,
diamonds are way more brittle than you think. You can actually crush them with the sole of your shoe.

Diamonds will burn at about 1562°F (850°C). House fires and jewelers’ torches can reach that temperature.

You wrote:
"If seen one come out of hot Coles and get dropped into water without damage"
=> No way. Nobody would even dare to do that with a diamond. Even if the fire would be too cold for the diamond to burn, it would shatter to many little pieces when put in cold water right after being in the fire.

Try to get a hold of a real natural diamond, maybe at a jewellers store. Then study it and then compare it to what you have. It is very unlikely you have a diamond.
Cheers, Herwig

[Kharv]

I appreciate your port skeptical is grate, I'm trying to prove it's not a carbonado not that it is... Won't complain if it is one, won't be surprised if it isn't... Best part of it come out not csrbonado I get to keep it... It's one of my favorite stones, was before the thought of carbonado was unlisted in me... Rare and beautiful in my opinion.