Featured Pieces of coral for jewellery. In discussion. Help.

I like the jewellery, among others, the coral jewellery. By this reason I consider that it is very important know the coral and they types or species. Many years ago, I read an article about the different species of corals used in jewellery and it take my interest in a strong way. Since this day, I have been collecting, different pieces of coral for trying to classify them.

Could you help me identifying them?

 

That is a LOT of examples crammed into one picture. Perhaps you could number them or arrange them so they could individually identified or discussed?

 

@Jal
This might work.

 

Yes, better!!!


Thanks cluttered!!!!

 

I think 1, 2, 4, 7, 8, 10 and 12 are Corallium rubrum, probably from Italy and Catalonia. But I don't dare say anything about the other pieces, I can't find any information. The 9 is very curious, maybe Japan?
I can take more pictures if is necessary

 

@Any Jewelry

 

That's a difficult one, Jal. I suspect they are all Mediterranean, except for the big one, #11. That one looks much like coral used in traditional bead necklaces from Nepal. Although the Himalayan countries used Mediterranean red, some coral is said to be 'red mountain coral'. The only information I have on that is that it is mentioned in several sources as fossil Coralliidae, so related to the precious corals we know now.

Could you show photos of #11 from different sides, and of a bead hole?
And you could test if it is naturally red coral by pressing cotton wool with acetone against the end of the bead for ca 30 seconds. If the cotton wool stains red, the bead is dyed.

And also a photo of the other side of #9, the big one with the white band please.

It looks similar to the white band in some of the beads in the photo below, these are very old Mediterranean red coral beads from an antique necklace from Yemen.



As you can see, some of the coral was also attacked by hole boring sea organisms (can't remember the name). Ca 1800 people started to be more particular about the look of coral, and these white bands and holes are hardly seen on 19th and 20th century coral jewellery.

Maybe nice to know, Yemen used to trade coffee for Italian coral. That is how Italy came to have such a coffee culture. The coffee was shipped from the Yemeni port of Mocha, another coffee-associated name.

 

Since you are studying coral, you might find this article interesting/useful:

https://www.gia.edu/doc/Spring-2007-Gems-Gemology-Pink-Red-Coral-Guide-Determining-Origin-Color.pdf

 

Number 9 also seems 'off' to me. Could we see some other sides & in close up?

 

Hello Any jewelry, thanks for your answer!
I think at least 9 and 11, they are not from the Mediterranean Sea.
You are giving me very interesting information about coral and Italy and coffee!
Now I don't have acetone at home, but I have tried the pieces with 90º alcohol and they don't release color.
Looking at many corals in recent years, I suspect that even genuine Mediterranean coral is dyed to enhance color.
I attach more detailed photographs for discussion.

 

Thanks Bronwen! it will be very useful!!!!

 

Thanks for the photos, Jal.
That straight piece looks even more unusual now.
The bead looks natural, and it is lovely.

Alcohol doesn't work, only acetone. Do you have nail polish remover? Most of those also work because they contain enough acetone.

 

Hello,
Finally I tested the corals with nail polish remover and none reacted. On the other hand, I tried a dyed coral and it didn't react either. Perhaps the product does not have enough acetone, even though it is its main ingredient? But I think it is not a solid test for modern dyes.
Also, I have been observing information from different species of coral, corallium rubrum, secundum, japonicum, etc., but it is too difficult to identify.
I learned a lot, but coral is still a pending issue.

 

Not all nail polish remover works. Most do, but some have too much other stuff mixed in.

It is (acetone), but some modern dyed coral has a protective coating.

It often is. It is easier when it is set in jewellery, because you have a reference of the location and the period.

 

The nail polish remover used have as the main product acetone and it is brand new. Moreover, the dyed coral tested have not a protective coating because I cut it to see the interior. Anyway when I found pure acetone I will repeat the procedure.
As you told, is easier recognise the coral set in jewellery, and it is more beautiful. We will continue learning about coral!!!