Featured What kind of coral is this?

Hum... the aceton test for dying isn't really conclusive!
I bought this massive 100" long necklace from China for 38.70€


having no doubt it is dyed bamboo coral (sold for salmon/pink color, it is as red as showed in the pic!), after reading your comment I tried your aceton tip on several beads, even soaked in a little cup, result: no trace of red on the white tissue, no discoloration on the soaked bead!
A close up of a hole shows same color inside!

Beads aren't glass, the pits and lines are those of coral

I still stand for bamboo coral
I'd greatly prefer if I could soften this bright red into the salmon I wanted originally !!!

 

Apparently the most conclusive test for coral is with a spectroscopy microscope.
I have used the acetone test on different coral beads, it has worked with all of my suspect coral so far.
You press a cotton bud with acetone on the same spot of the coral for 20-30 seconds. Some sites say rub, but I find that pressing for a longer time works better because the acetone stays in one spot. If the cotton bud is stained, the coral is dyed. This method won't remove all of the dye, the coral still looks the same.

I can imagine, I prefer salmon coral as well. And love angelskin coral.
I know red coral can be professionally bleached. Some Dutch bead sellers order their Italian red coral bleached to the darkish salmon colour, which is preferred here in the Netherlands. I have no idea which method is used, just that it is done in Italy.

 

@kyratango , maybe a mild hydrogen peroxide formula will do the job. Bottom of this page:
http://www.jtv.com/library/dye-staining-bleaching-gemstones.html

I don't know if the result will look good, hope it won't come out blotchy.

 

The bead I soaked stayed for 20 seconds, the tissue rubed after that got no color on it
Previous beads I bought slighly discolored in sun (they hang on a window knob!) but they weren't as bright red as these

Thanks for your link , I tried in the past with a hair bleacher, gel formula, with no significant result

 

But I bet your hair looks great.

Maybe the peroxide wasn't strong enough, the term 'mild hydrogen peroxide formula' isn't very precise, and I haven't found any mention of percetages yet. If I find anything, or maybe another method, I'll let you know.

Or maybe the coral has been treated with a synthetic stabilizer (resin), like they use for turquoise, or they have some sort of coating?
Btw, did you test the beads with a diamond tester, or with lemon juice?

 

Ha, lol for my hair! Trying to get paler reflects...

I think the coral has been coated... Perhaps Chinese realized people wearing dyed beads won't enjoy getting their clothes or skin dyed in red too!

I don't have a diamond/stone tester, but I could give a try with lemon or vinegar Thanks for the idea!

 

Just tried with vinegar! Nothing happened on the outside, but in a hole I got few tiny bubbles and some red on the tissue when removing the acid
They are coated!

 

Yes, that's a coated reaction. They are real coral, that's why you got the bubbles from the hole, but they have had a complete makeover.

 

Don't think I saw this at the time, but want to share this pdf on coral & coral colors with you.

 

Great link Bronwen! Thanks

 

A bit technical, but much good info for those of us who need to know these things.

 

Absolutely. Thanks.

 

Any Jewelry, are you a coral collector?

 

I didn't really start out that way, but since I grew up in a 'coral wearing country' (my term), and collect ethnic jewellery, my coral jewellery collection keeps growing.
I am in the Netherlands, and many Dutch regional costumes can't do without lavish amounts of Mediterranean red (and salmon) coral. I have some coral jewellery that was passed down through the family.
Traditionally red coral was regarded as having medicinal properties against anemia, so important for women. In other cultures red coral is worn for the same reason, and is often seen as having talismanic properties.
I also have some black coral, from Yemen and Indonesia. In both countries it is thought to have spiritual properties, Indonesians also wear it as a remedy for arthritis.
As for the other colours, I love salmon and angelskin coral, and I have one rare white coral Shaman's bracelet from Madura, Indonesia.

 

Black coral also came from Hawaii, and vintage pieces still do or did, but they don't harvest it any more. Coral in Britain was often given to young woman, and used as part of teething rattles for babies most likely for the same reasons.

 

They probably don't harvest it anymore because trade is regulated in many areas. It is not an endangered species, but it has been put on a cites list of species that have a retail restriction.
The Yemeni black coral necklace I have is 19th century, the Indonesian black coral pieces date from ca 1890-1970s. I wouldn't buy it new, although it isn't prohibited yet.

 

I probably wouldn't either, but then I haven't seen any new coral other than Chinese dyed pieces in years.

 

I get lucky once in awhile....finding the older coral is a rare occurance.