Does anyone know if it is OK to put red coral beads into an ultrasonic cleaner? If not, what is a good way to clean them? Thanks…Rob
Thats a BIG NO! No detergent either. Pickle will also do irreversabile harm. Only lukewarm water and a very mild soap.
Master The Skills Of Oil Red Coral At Home And Be Successful.
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Jo…Thanks! In the back of my mind, I thought that I had read that Red Coral should not be cleaned with anything other than water and detergent. The coral beads are on a very nice pendant along with traditional filigree beads. My son bought them for his wife when he lived in Tunisia. He was covering the goings on in Libya until it was too unsafe to live there and moved to Tunis…Rob
can’t be too careful with organic materials… coral should be treated like pearls and also amber…
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Thanks all for the caution on cleaning coral. I just used a bit of mild detergent and a soft brush and they are clean. The beads were a challenge as I didn’t want to get near the polishing wheel with this necklace. I cleaned them first with Wrights cream and then the same as the coral beads. Everything looks great and my son is happy…Rob
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I have some precious black coral from Makapuu, Oahu, Hawaii…Jack Akerman was a professional scuba diver and a friend of my late father’s. Jack went on to found Maui Divers, which now is a high end jewerly store specialising in coral and pearl jewelry. He gave my father a couple of thick pieces that could be cut into cabs. Also a coral “tree” which was a small coral fan with thin branches that were too small to cut.
Black and gold coral are concholin based, a proteinaceous substance with calcium carbonate. These corals have been over harvested and have become rare. Pink and red coral contains more calcium carbonate…about 20 years ago I visited the Maui Diver’s show room in Honolulu. One of the sales people sold me three gold coral cabs… the management refused to sell them at first, but finally did when I told them about Jack Akerman who had founded the company 65 years ago… I made a black, gold and pink/red coral bracelet out of alternating colors set in gold. Precious corals grow in deep water. It takes over 100 years to grow a branch a half inch thick. A one inch thick mainstem could be as old as 300 years. The coral beds off shore of Hawaii have been protected… harvesting is done sustainably and by ROV’s… 300 feet deep is at the limit of scuba diving…
Most of the coral on the market now comes from the Southwestern Pacific and the Indian Ocean… havesting is done indiscriminately with draglines… One can imaging how destructive this technique is to all deep marine life… I am afraid that such indiscrimate dragging of the deep will destroy the coral beds and lead to near extinction. Coral will become depleted and the price thereof will skyrocket.
Take good care of your coral and treat it gently… mild dish detergent or even shampoo with water is the only way to clean it…ultrasonic cleaning will loosen the growth layers… coral has rings like a tree…expect the value of coral to increase as coral depletion continues unchecked in developing countries…Aloha to all !
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Hi Rob excuse the ignorance but what is Wrights cream?
Australian hobbyist here - very curious. I’ve never heard of it.
How do you use it and for what?
Cheers
Willie
It’s a real mild tarnish remover in a paste form with no abrasive. I apply it with a sponge or just my fingers, scrub a bit with a soft brush, rinse with warm water and dry with a clean towel. You should be able to find a similar product, just make sure that it doesn’t contain any abrasive material. Jeffrey Herman’s site used to have a very comprehensive discussion of these types of tarnish removers. It may still be up…Rob
Gong through some folders of old documents I came across this handout from the Intro to Gemology class at FIT. If lists all the commonly used jewelry gemstones with their reactions to various processes. I thought it would be useful to post on Ganoksin. It might be good if the admins add this somewhere on the main site as well.
Sorry if the columns and lines are a little irregular. I scanned this and the OCR software did the best it could.
FIT Gem Chart.pdf (105.8 KB)
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Thanks for the information. Does FIT still have a program where this type of information would be useful. I ask because my grand daughter will be a Junior there in the fall and has never mentioned a gemology class. They do have a metals program and maybe it is part of that. Thanks…Rob
There are six gemology classes, as part of the jewelry design program. They’re nothing like a full GIA course, but go further than just an overview.
Thanks! I will look at their current online catalog…Rob
Thanks for that Rob
One tarnish remover that does not involve any abrasive material is to put the tarnished silver in warm to hot water (depending on whether there are heat sensitive stones involved). Place a piece of aluminium cooking foil in the container and add a couple of tablespoons of bi carbonate of soda. Make sure the bi carb is fully dissolved before adding your tarnished item. After the tarnish is removed the piece just needs a polish with a suitable silver cloth.
That’s a big Nope from me. This process has the same effect on silver as Tarnex does. Every one who makes and or cleans and repairs silver should have this priceless document on hand. Silver polishing, silver cleaning, and silver storage
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That document is still up. And personally I would much rather put my faith in GIA rather than FIT. https://www.thegemlab.com/media/wysiwyg/Digital-Gem-Cleaning-and-Display-Chart.pdf
Thanks for sharing the GIA stone care document Jo. We have an old laminated copy on the wall where I work. I’ve always wanted to get a copy for my own.
Thanks again!
Jeff
Jo…Thanks, this is a good bit of information from a trusted source…Rob
I have done this, but only with fine chain. I don’t like the finish as it is an electrolytic process that probably removes metal. Also, remember that you may want some tarnish in a piece with lots of relief as it gives the piece a 3D effect after the high spots are polished. If you remove all of the tarnish, this goes away…Rob
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Thank you Jo for that as you say quite priceless info on all things related to silver care.
I am happy to stand corrected!
Cheers Willie
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I completely agree with you:
using aluminum foil and baking soda does work quickly… it leaves a microscopic layer of gray colored fine silver as the aluminum oxidizes and reduces oxidized silver. Definitely not a good idea of silver plated kitchen ware, dinner service pieces or anything that is silver plated… after treatment, items still have to be polished which strips off the fine silver… repeated treatments will strip off the silver plating.
This technique could be used on heavy solid silver pieces without fine designs…but not on anything thin and delicate… avoid oxidizing substances and particularly chloride… silver reacts with chloride (as in salt) to form silver chloride that also is gray and gets stripped off when polished… a friend of mine who is a clean freak when it comes to cleaning dishes and silverware learned it the hard way when she mixed beach with dishwashing soap to kill germs… exposure of silver plated tableware to bleach caused the plating to oxidize and bubble up, ruining the surface…
This is going off topic from the original question about how to clean coral… which is already settle… just a mild detergent and water will do… and avoid acid at all cost!.. even lemon juice will attack the calcium carbonate in the coral and cause a stain… the same goes double for pearls…and shell… all have aragonite, a form of calcium carbonate that will not tolerate any acid…pearls are super delicate and need only to be wiped clean with a clean soft cloth…I should also add that malachite and azurite are also carbonates and will be ruined with acid.
So far as other gemstones are concerned, the GIA guide is the best compact summary of how to care for your precious and semiprecious stones…ultrasonic cleaning works only on tough hard stones that are not full of fractures, inclusions of other weak points…emeralds always have fractures and inclusions… corundum stones (saphhires and rubies) and diamonds generally are pretty tough and will withstand ultrasonic cleaning… but there are gentler methods that can be used to clean them… toothpaste has hydrated silica in it… could scratch anything softer than Moh’s hardness 7.5… thermal shock is listed as to be avoided on everything… all organic materials- pearl, amber, coral, shell, ivory and bone, are very soft, scratch very easily and have to be treated with extra care…