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 Post subject: Extremely rare black diamond at a rough state
PostPosted: Thu Dec 06, 2012 12:14 pm 
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Dear friends,

I discovered that I own one of the biggest black diamonds in the world since years without knowing that (a family decoration stone put in the living room with some fossil).

When I discovered it's hardness (unusual) I contact a gemologist to study this stone, he provide me the following details:

Stone : Carbonado
Size (approximative) : 4CmX3CmX3Cm
Color : Natural Black with some similarity with Onyx color
state: Natural
Form cristalline : rhombododécaèdre (in french)
weight : 127,6 Gram (638Karat)
Coef Mohs Scale: 10

Pictures can be consulted in this link:
https://docs.google.com/open?id=0Bwy9c8 ... Xp2TVJSUFE


I contacted a jeweller in Belgium who bargain it and told me: its price is no more than 4000USD cause of its polishing that will be extremely hard and will take at least one year. After polishing it will be sold at 90'000USd and 90% of this price will just cover polishing expenses.

when I make a look around the internet and record holders of biggest diamonds in the world, I build up an opinion totally different about the value. I think it's much higher than I was informed.

I open this topic to hear from you what do you think about this case.

Thank you in Advance :)


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 Post subject: Re: Extremely rare black diamond at a rough state
PostPosted: Sun Dec 09, 2012 3:21 pm 
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It seems to me, someone couldn't put a direct value on something that rare. These are the types of things that are worth what you can get for it. In that scenario, I would want to have a highly qualified well prepared auction to even roughly guess the value.


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 Post subject: Re: Extremely rare black diamond at a rough state
PostPosted: Sun Dec 09, 2012 10:43 pm 
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I moved this topic because it was definitely NOT a forum announcement.

Carbonado is a porous, polycrystalline variety of diamond, opaque grey to black by definition, used as an industrial abrasive and for drill bits. It is not suitable for use in jewellery.

It has mineralogical interest, but it is not gemologically relevant.

I think the jeweler you spoke with in Belgium is misinformed.

Here is a link to a company which sells carbonado. You can contact them and ask for price information:
http://kakadiyagroup.blogspot.com/2010/ ... wn-as.html


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 Post subject: Re: Extremely rare black diamond at a rough state
PostPosted: Mon Dec 10, 2012 12:53 am 
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Dear skywalker, Welcome to gemology online.
To me this is irradiation smokey quartz (This is my opinion) because one my friend send some specimen of kunzite with quartz for irradiation. After irritation the quartz changes it color just like your picture.

Very sorry that I have not picture still available. Once again I say that this my personal opinion.

with best regards

HUK

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 Post subject: Re: Extremely rare black diamond at a rough state
PostPosted: Mon Dec 10, 2012 2:30 pm 
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Osman khattak wrote:
Dear skywalker, Welcome to gemology online.
To me this is irradiation smokey quartz (This is my opinion) because one my friend send some specimen of kunzite with quartz for irradiation. After irritation the quartz changes it color just like your picture.

Very sorry that I have not picture still available. Once again I say that this my personal opinion.

with best regards

HUK


Thanks Osman for the reply, but a quartz is 6,5-7 and not 10 at Mohs scale!!!! (The Gemologist make the expertise)


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 Post subject: Re: Extremely rare black diamond at a rough state
PostPosted: Mon Dec 10, 2012 5:50 pm 
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 Post subject: Re: Extremely rare black diamond at a rough state
PostPosted: Sat Jan 05, 2013 7:33 pm 
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Joined: Thu Oct 11, 2012 6:29 pm
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It's glass, slag, or smoky quartz.

The "gemologist" that studied it is an idiot. There are no crystal faces, but it's described as "Form cristalline : rhombododécaèdre (in french)"

Worth 90k... which would just barely cover CUTTING COSTS??? A year to polish???

AHAHAHAAHAHAHAHAHAHAHA!

Nice troll.


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