How old are diamonds, rubies, sapphires and emeralds

[Cave Keeper]

Are the top four precious gemstones older or younger than the fossils of the last dinosaurs which apparently became extinct about 65 to 75 million years ago?

 

[strmrdr]

diamonds older

dont know about the rest but my guess is likely younger in most cases.

One of the experts can tell you if im guessing right :}

 

[valeria101]

I like this one. Diamonds are not all of the same age (see HERE) either. The same article mentions that the age of diamond deposits is not the same with that of diamonds themselves.

I doubt there is a common age for a gem in general, but there is a geologic age for each deposit. Hopefully someone took some time to come up with a ballpark already otherwise it may take some time to figure one out. Honestly, it didn't occur to me just yet

 

[Cave Keeper]

Trust our dear Valeria101 to come up with a good link. Thanks.

So diamonds are 1 to 3.3 billion years old! No wonder diamonds are forever!

I asked this because I read somewhere that the Japanese emperor and empress gave their daughter-in-law ammolite jewelry as a wedding gift. After that, the Japanese people went wild over ammolite, especially because they reasoned the 70 million year old fossillized gem represented the eternity of romantic love. They also called ammolite the Heaven Is Vast And The Earth Is Ancient stone.

Not that I wish to cast aspersions on other people by proving them wrong; anyway, 70 or 3,300 million years, what's the difference to us, human beings, whose estimated existence as Homo Sapien sapien is only 0.1 million years?

 

[valeria101]

Actually, I am not very sure if the info down that link is not closely linked to the same sort of hype that hit Ammolite in Japan.

Someone with better knowledge of geology would know how dependable these datings are. I would think that diamonds are still being produced by continental subduction (mentioned by one hypothesis about the SE Asia deposits)... for what that matters.

Who needs to rank gems by geologic age

What do you do about pearls then ? This sounds like a poetic excuse to take diamond wearing away from fashion: "eternal" meaning "longer lived than the latest fashion trend". There must be better things to say about gems than their age.

 

[Cave Keeper]

Google asks "Do you mean subduction?"

Val, thanks for enlightening me. So diamonds could be less than a billion years old, provided they're found in continental drift faults such as along California or Taiwan. Give a few more years and such places could be rich in diamonds.

But in the case of Kimberlite deposits, the diamonds are still at least one billion years old.

Perhaps not to gemologists, but crystalogists and white witches seem to value the age of stones more. Quite many of them associate the power of wisdom with the age of stones. Right now, there is an argument over whether ammolites have more energy force than other crystals. Maybe age is a factor?

 

[Cave Keeper]

Here's something which may support your doubts about that 1 billion to 3.3 billion years age for diamonds.

Just happened to talk to a recent dropout from Purdue. Anyway, this AP Scholar points out to me that diamonds couldn't have been formed that deep down in the Earth. According to him, the temperature at those depths would have incinerated any diamonds, turning them into ashes.

I thought he had a good point then. But now that I think of it, perhaps he forgot to consider the pressure at those depths, too. Oh well, maybe that's why he's a dropout and not me.

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On 9/7/2004 11:53:37 AM valeria101 wrote:
Actually, I am not very sure if the info down that link is not closely linked to the same sort of hype that hit Ammolite in Japan.
:
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[valeria101]

White magic !!? What next

I just do not have any good source on the geology of diamond deposits. The historic usage of diamonds was of more interest to me than their geologic age... Garry is a geologist, he would know

Any idea who came up with those billions and the fun fact that diamond matrix is younger than diamonds?

IMO, "Burning" is too generic a term for molecular phisics.

 

[DiamondExpert]

Your Purdue dropout is talking rubbish...your idea of considering the extreme pressures is right on, PLUS the fact that there isn't any O2 down there so there will be no incineration.

The fact that garnets are sometimes found as inclusions within diamond crystals attests to other gemstones' extreme age also, but not all gemstones are that old...but what's a few hundred millions years between friends anyway?

Diamonds are old enough that Carbon dating techniques do not work at all on trying to determine their age.

 

[valeria101]

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On 9/9/2004 4:00:30 PM DiamondExpert wrote:



Diamonds are old enough that Carbon dating techniques do not work at all on trying to determine their age.
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I was hoping to hear this... since I did hear it once before.

One of my former colleagues did work on Carbon dating in college (now she is teaching physics). She laughed at the idea that the geological cycle of carbon could be used for C dating.

The note about garnet inclusions is very neat

There are quite a few gem minerals that appear as indicators of diamond deposits. Siberian kimberlite and the diamond deposits in Finland also come with a few types of garnet, diopside and perhaps others too. Not that many care about these mere 'diamond indicators'.

 

[CaptAubrey]

carbon 14 dating is only good for the last 50,000 years because of the half-life of 14C.




diamonds are dated using uranium isotope dating; uranium is a common trace element in zircon, which is a fairly common inclusion in diamond.




ironically, carbon-14 dating might be useful for determining whether you have a synthetic diamond made from human remains.

 

[valeria101]

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On 9/9/2004 4:43:55 PM CaptAubrey wrote:


carbon-14 dating might be useful for determining whether you have a synthetic diamond made from [].
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Yiks... how can they!!!

Just horrible...

Anyway, do you know where those popular astronomic numbers come from (source for the dating)?

 

[CaptAubrey]

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On 9/9/2004 4:51:07 PM valeria101 wrote:







Anyway, do you know where those popular astronomic numbers come from (source for the dating)?

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there was a series of articles in the mid-late 80s/early 90s on the subject in nature. this is the earliest one i can find online:

http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v346/n6279/abs/346054a0.html

as i recall now, there are actually a variety of radioisotopic dating methods used, not just uranium-lead.

 

[DiamondExpert]

Thanks for the link Capt, and your always useful info.

 

[Cave Keeper]

Oops, I misunderstood him. Apparently he said something about 'vaporise' or 'molten', not 'incinerate'.

However, he had another point about those diamond deposits in those rocks which were supposed to originate deep down the Earth. Said those diamonds were initially liquid carbon at those depths. As the rocks at those depths rose, they cooled down. The carbon which were trapped in those rocks began to crystalise. He said there should be a difference of a few million years between the formation of the rocks and for the carbon to turn into diamonds subsequently. So according to that Purdue dropout's reckoning, the rocks were older than the diamonds, not the other way around!

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On 9/9/2004 4:00:30 PM DiamondExpert wrote:
Your Purdue dropout is talking rubbish...your idea of considering the extreme pressures is right on, PLUS the fact that there isn't any O2 down there so there will be no incineration.
:
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[CaptAubrey]

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On 9/10/2004 10:20:14 AM Cave Keeper wrote:





Oops, I misunderstood him. Apparently he said something about 'vaporise' or 'molten', not 'incinerate'.

Said those diamonds were initially liquid carbon at those depths. As the rocks at those depths rose, they cooled down. The carbon which were trapped in those rocks began to crystalise. He said there should be a difference of a few million years between the formation of the rocks and for the carbon to turn into diamonds subsequently. So according to that Purdue dropout's reckoning, the rocks were older than the diamonds, not the other way around!

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i think his confusion is arising from the fact that the mantle rock diamonds form in is not the same as the rock they are emplaced in. kimberlite magma rises through the mantle and picks up diamonds along the way, passing through these older rocks on the way to the surface. that at least is the theory (there is a lot of disagreement about precisely how all this occurs). the diffference in ages between diamonds and kimberlite, however, is well-established and widely accepted.

 

[Cave Keeper]

Oops again! It was I who misread the article and conveyed an incomplete picture to him. I assumed wrongly that the diamond material were originally contained in the kimberlite itself which rose up to the surface. Thanks for pointing this out. No wonder I wouldn't even have got into such esteemed universities myself.

So diamonds may really be 3.3 billion years old after all. Well, there's always moonrocks if anything older is needed for bragging rights.

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On 9/10/2004 12:59:08 PM CaptAubrey wrote:

i think his confusion is arising from the fact that the mantle rock diamonds form in is not the same as the rock they are emplaced in. kimberlite magma rises through the mantle and picks up diamonds along the way, passing through these older rocks on the way to the surface. that at least is the theory (there is a lot of disagreement about precisely how all this occurs). the diffference in ages between diamonds and kimberlite, however, is well-established and widely accepted.
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On 9/10/2004 10:20:14 AM Cave Keeper wrote:


Oops, I misunderstood him. Apparently he said something about 'vaporise' or 'molten', not 'incinerate'.

Said those diamonds were initially liquid carbon at those depths. As the rocks at those depths rose, they cooled down. The carbon which were trapped in those rocks began to crystalise. He said there should be a difference of a few million years between the formation of the rocks and for the carbon to turn into diamonds subsequently. So according to that Purdue dropout's reckoning, the rocks were older than the diamonds, not the other way around!
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