John has a beautiful strand of cherry-colored Bakelite beads, also called "cherry amber" by some. The beads are phenolic resin, and the cherry color comes from heating the beads, which advances the cure of the phenolic resin. John told me that the Africans use the technique of heating the beads immersed in palm oil. That may add to the lovely patina.

I've been doing some experiments with heat-treating phenolic resin beads to show how the color change progresses. Some phenolics darken to a dark red / mahogany color while other retain a more brown tone.

For comparison to the Picard strand, here is a before & after of an old (presumably 1920's-1930's) phenolic bead that was heated for one hour at 350 F. I'm using a small lab oven for these experiments - I do not recommend that you use your kitchen oven, although there should be only a very tiny amount of free formaldehyde or phenol that would come off an old phenolic bead. Also I should warn that there are some plastic beads that look a lot like phenolic resin and heating them to 350 F may produce significant odors or other problems - I'll report on this specific topic later.

Did not know that this resin would change color with heat.
Interesting to see this example of before and after.

Yes, and one way to prove that a bead in not phenolic is to heat it to 350 F. If it gives off a strong styrene odor and doesn't change color, then it is not phenolic resin. Found this out the hard way!

In case you want to try this yourself - place the suspect bead in the oven at 350 F for only a few minutes (less than 5). If the bead is phenolic resin, there will be minimal color change in 5 minutes, and no odor. If the bead is polystyrene or polyester, the heat will knock the gloss off and the odor will be strong. Don't inhale a lot of it!

The bead may start melting so place it on a piece of tin foil.

Please see my follow-on posts (coming soon) on these types of plastic beads.

Hi Rosanna

Fascinating reading your posts regarding the change in phenolic beads.

Just wanted to quiz you further if that is okay.

You say the non-phenol beads give off a bad odour in under five minutes. How long does the colour change take in genuine beads?

Also when you hold a successful colour change bead to the light what effect is shown? Is it that beautiful marble cloudy effect that you see so often in these so called "cherry amber beads"?

Hope you don't mind me asking.

Regards

Calum

Good questions!

The oven I have doesn't have a window, and I don't have an exact answer about how much time it takes to start seeing a color change, but after 10-15 minutes at 350 F (177 C) the beads are darker. You may be able to see this at 5 minutes. They will continue to darken as long as they are heated, until they become pretty much black. I don't know how long it will take to go black - and it may be a long time, like a week. If I decide to blacken a bead I'll let you know - and I'll start by using a higher temperature to speed it up.

Second - the beads I've been experimenting with are opaque to start with. I have not used any translucent beads in the heat experiments, since I don't have any amber-colored, translucent or semi- translucent beads to play with. Phenolic resins could be dyed with many colors, so the almost clear cherry-colored beads may have been dyed that color to start with. The semi-translucent, cloudy marbled effect that you refer to - could have been a bead that was dyed that color originally, or could have been heat treated. I just don't know how prevalent heat was used to change color vs. dye in the original mix. Of course, a dyed bead could also be heated to darken it as well.

I'm concentrating on the beads that I'm pretty sure were traded to Africa, where I'm also pretty sure the heat treatment was done. I'm showing here another strand I purchased recently. The lightest red beads - not sure if they were heated or dyed that color to start with. For the darker beads, all the way to black, I'm 99.99% sure they were heated. You can see one bead near the bottom of the strand that was scorched on one side, as evidence. Close-up of that bead in the second picture.

Hi Thanks for the reply. I may have to do some careful experimenting myself and see what I end up with. Regards Calum

I would like to say again - please do not heat any beads of any kind in an oven used for food. Maybe get an old toaster oven and do this outdoors, away from any flammable materials. Be safe!

John has a magnificent strand of intricately carved phenolic resin beads. These beads were made from larger, plain beads (I assume). I wanted to document these wonderful beads for a possible book on phenolic beads traded to Africa. Regardless of how the book turns out - I'm having a lot of fun finding and documenting all sorts of information on phenolic resin and the beads made from it.

I should add that these beads were used as hair ornaments, and I would appreciate any pictures that people may have of the beads as worn in Mauritania. Christine - I think you said you might have some from your trips there?

I've never seen anything like these before.. So beautiful, so intricate. What is the aproximate age? Does anyone have suggestions about where they could be purchased? Thanks so much!

They are not often found for sale, anywhere.

The strand at the Picard Museum is the finest group of these beads that I know of. I have about 8 in my collection. Keep a look out for them - they are often mixed with the more solid diamond shapes on market strands. But expect to pay a steep price - hundreds of dollars per bead, many thousands for strands of carved phenolic beads from Mauritania. These are rare beauties! And most are likely in the hands of collectors now, or still on the heads of women in West Africa.

About two years ago I saw a woman walking around a bead show with about 80" of these beads around her neck. My eyes just about popped out! I'm sorry I didn't get her name and make an appointment to photograph them. I did recall asking if they were for sale, and she laughed and said, "no way".

Wouldnt you know that the most beautiful beads are also among the rarest! I'd love to own just one of these beauties. When I couldn't find any on the Picard site I figured they'd be awfully hard to find... Thanks so much form the information. I'll keep an eye out, but think it must be a long shot to hope they might be mixed in other beads . especially now when people are going over old strands to cherry pick for their own collections. (Well, I know I am!)

Another fantastic strand at the museum is a combination of silver and phenolic beads. Also sourced from Mauritania, or the general Maghreb region (North-west Africa). Some of the carved phenolic beads have been decorated further with some sort of dye or paint (see close-up).