What is this button made of?

[CaptainBoj]

Hi guys, I didn't know where else to ask this question, but my mother in law was throwing out her parents' old clothes and said i could keep the buttons.
I was cleaning them up a bit and found one that smelled faintly like a smelly old fish for a little while after i washed it with warm water.

Anyone know what plastic it could be made of?
I tried looking at celluloid and bakelite but it doesn't seem to fit either of those descriptions

Here are some photos:
Front: https://i.gyazo.com/d940e7147bb8a5a07087db8051ac0c89.jpg
Back: https://i.gyazo.com/8e15de2106ce39ef46441019dcb00a2a.jpg

Any help would be appreciated

 

Amazon Forum Fav 👍

Agony and Death on a Gold Rush Steamer: The Disastrous Sinking of the Side-Wheeler Yankee Blade - Grab it through Amazon!

[vpnavy]

For those members who hate hitting links - here are the pictures!

​

 

[Tpmetal]

Goodyear rubber buttons? Hard to tell from pics. I do know there are certain plastics that break down to smell terrible as well.(old cheap screwdriver handles an example)

 

[CaptainBoj]

Haha sorry, i'm not very good at embedding images, thank you for that

Goodyear rubber buttons? Hard to tell from pics. I do know there are certain plastics that break down to smell terrible as well.(old cheap screwdriver handles an example)

It could be rubber, it does have a bit of friction to it

What does formaldehyde smell like? I saw something say that certain plastics smell like that but i've never smelt it myself so i'm not sure what to compare it to hahaha