Radio Lady Discusses: Can you carbon-date a shell?

[Radio_Lady]

I've been decorating a main floor bathroom in a Hawaiian theme and I have been handling coral and shells all week.
It's been fun. I'm almost done with the project. The room looks super-beautiful and my two grandkids will be thrilled.

But a question remains in my mind: Is it only animal material that can be carbon-dated? What about the mineral shells we find on a beach? How old could they be and can that be proved?

If you're more scientist than romantic, and know the answer, I'd like to hear from you.

In peace,

Radio Lady in Oregon

[IcyPeas]

1. Coral? Is that Live Earth friendly coral?

http://www.worldwildlife.org/coral/index.cfm


:shrug:

[Orsino]

2. Calcium carbonate.

Yep. It could be carbon-dated.

[Radio_Lady]

5. Thanks, Orsino. Another question: How old could any shell possibly be???

These were acquired on the Hawaiian islands mostly.

But some of them may have been purchased at yard sales.

Anyway, thank you.

There was a book that intrigued me when I was a child. It's called "The Lion's Paw." Name of a shell as I recall.

[Orsino]

7. Shells have been around for hundreds of millions of years.

And chalk deposits, such as Dover's famous white cliffs, for just as long. I think radiocarbon dating is only useful to about 50,000 years ago.

[trof]

3. What caliber?

:rofl:

[JustABozoOnThisBus]

4. No matter, gunpowder contains carbon, so yes

you can carbon-date the things.

The nitroglycerin in smokeless powder also contains carbon.

But sometimes the year is stamped on the base of the cartridge. Those are easier to "date", just need glasses.

:hi:

[Radio_Lady]

6. OK, but the subject was shells from the ocean, not gunpowder. No worries.

[muriel_volestrangler]

8. Without looking anything up, there might be problems

Carbon dating depends on the carbon 14 produced in the atmosphere from cosmic rays hitting nitrogen 14 atoms, I think. The carbon is then taken by by plants photosynthesising, and then animals eating them. The rate at which that gets into shells in the ocean might be different - which, if it's predictable, would just mean a possible adjustment to allow for it being in the ocean, but the way carbon gets there might be too unpredictable. I think that makes it a good question, which would need someone from the field to answer.

[JustABozoOnThisBus]

12. I knew that, RL, but that darned "trof" ...

brought up the caliber of cartridge "shells", so I got curious about the carbon content of modern propellants.

In parts of the midwest, if you ask for a "shell", the bartender will pour you a small glass of beer. That's also not relevant - if you have to carbon-date a beer, it's probably stale.

:rofl:
:hi:

Any idea what it costs to have something carbon-dated? Or is this just something you get a college student to do off-hours in the lab? In which case the beer becomes relevant, as payment-in-kind.

[EstimatedProphet]

9. Yes

[Radio_Lady]

10. You people are so erudite that it is truly amazing.

I'm struggling with costochondritis this evening and my chest is hurting like hell. The medication is supposed to work, but not at this dose.

Going to bed.

"Say goodnight, Gracie."

[EstimatedProphet]

11. Thank you