Search Results for phenolic plastic since Wed, Nov 15, 2023, 22:01:52

The following 2 messages have been found.
(Search pattern:phenolic plastic, since Wed, Nov 15, 2023, 22:01:52)

Dissections of "cherry amber" phenolic resin beads
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Posted by: Rosanna

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05/14/2021, 18:40:12

I did a bit of work over the last year dissecting "cherry amber" beads and found that all of them had clear or cloudy yellow interiors. Based on an admittedly limited sampling, my hypothesis is that a large majority of old phenolic beads that we now refer to as "cherry amber" started life as faux (yellow) amber. Oxidation reactions at the surface slowly turned the beads a distinctive dark burgundy color. This behavior of old phenolic resins has been documented by others, but I think I may be the first to use dissections of beads in order to show the thin outer dark layer and the original interior color(s).

Here are a couple of the beads I sectioned. My full report on the subject was recently published in The Bead Forum, and can be accessed on ResearchGate. I also show an almost black phenolic bead that has a translucent green interior.

https://www.researchgate.net/publication/351364958_Cherry_Amber_Phenolic_Resin_Beads

Re: Dissections of "cherry amber" phenolic resin beads/interesting
Re: Dissections of "cherry amber" phenolic resin beads -- Rosanna	Post Reply	Edit		Forum	Where am I?

Posted by: AnneLFG

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05/18/2021, 14:10:23

Hey Rosanna, When you heated the Phenolic Amber beads did you ever cross section them to see if the darkened color went all the way through VS surface? As well- the beads heated in Africa that were darkened by heating? I don't recall reading that, but I'm betting you did.

The fact of phenolic amber beads changing color because of oxidative chemical reactions over short and long time periods is a great help in understanding what is causing variations in appearance of some beads. As well as, of course the fact of originally dyed beads, and beads intentionally manipulated in Africa by heat, and reshaping, drilling, etc. I suppose the cracked beads with dark veining are the result of "off gassing" / air introduction as the dark veining appears to follow the cracks.
Thanks, Anne

Bead lover, collector since Age 15, semi-retired had wholesale/retail bead, folk art, tribal art store Lost and Found Gallery for 25 yrs. in DT Greensboro, NC

Modified by AnneLFG at Tue, May 18, 2021, 14:12:35

Re: Re: Dissections of "cherry amber" phenolic resin beads/interesting
Re: Re: Dissections of "cherry amber" phenolic resin beads/interesting -- AnneLFG	Post Reply	Edit		Forum	Where am I?

Posted by: Beadman

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01/30/2025, 15:17:33

The topic of heating phenolic plastic beads to change their color from yellow to red was covered in my 1976 article for the Bead Journal. I referred to the fact that some African beads were only superficially red (and remain yellow in the interior), versus those that become entirely red through heating—as I demonstrated myself. These are shown on the cover image for Part II (The Bead Journal, Volume 2 Number 4).

A long discussion of "Faturan" and issues of making plastic beads can be found here:

http://beadcollector.net/cgi-bin/anyboard.cgi?fvp=%2Fopenforum%2F&cmd=iYz&aK=222374&iZz=222374&gV=0&kQz&aO=1&iWz=0&fbclid=IwY2xjawII4YVleHRuA2FlbQIxMAABHRH28LkRFRxN95MBBGSHk6rf9hzwaqQDXmfzUUhvYzmhUnpHfKepAQT48Q_aem_9tzWuZkPevNLBCUteGxSZg

Another episode in tracking Chinese beads through Miriam Haskell designs
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Posted by: beadiste

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01/17/2025, 21:27:28

Latest blog post touches on the question, "What do you do when the exotic imported beads you're using run out and you can't get more because your countries are at war?"

Some very odd beads in this suite of "Chinese lantern" charm jewelry attributed by lore to the Miriam Haskell workshop. The only Chinese beads in these necklaces and brooches are cloisonne dragon beads and carved 1930s cinnabar.

The rest of the beads are a truly odd assortment -
a black bumpy bead I posted about here awhile ago, that seems to be blow glass with a blackened silver coating
Lampwork beads from ... Venice? Czechoslovakia? post-WW2 Japan?
Rhode Island filigree bead (we'll see more of this one, stay tuned)
Phenolic and non-phenolic plastics
Painted wood
Japanese molded composition
Sea bean seeds
Crude pressed glass? Prosser? flying saucer beads and lily caps
Stone chip inlay probably from India
A mysterious dentable black bead with faux-cloisonne designs (black bead with red dots, second pic - also appears with stylized floral pattern in other pieces)
etc

https://www.beadiste.com/2025/01/puzzling-evidence-suite-of-chinese.html

The following 2 messages have been found. (Search pattern:phenolic plastic, since Wed, Nov 15, 2023, 22:01:52)

The following 2 messages have been found.
(Search pattern:phenolic plastic, since Wed, Nov 15, 2023, 22:01:52)