Chemical Forums

General Forums => Generic Discussion => Topic started by: alodg on October 31, 2016, 10:25:47 PM

Title: Turning a £1 coin black?
Post by: alodg on October 31, 2016, 10:25:47 PM

This British pound coin came through my till the other day, it dirty to the point of being black, other than the raised details.

Is there a way to make the exterior of a pound coin react so that it turns black, then I could rub the raised print to get the same effect, I like it.

Apparently the composition is: Nickel-Brass (70pc copper, 5.5pc nickel, 24.5pc zinc).

https://cl.ly/0h3r0s3J2N1U

Thanks!

Title: Re: Turning a £1 coin black?
Post by: Hunter2 on November 01, 2016, 05:35:55 AM

For this you can use sulphur liver. It is a Polysulfide. The sulphur reacts with the copper in the brass and forms coppersulfide.

http://www.sunsetcrystals.com.au/xl-gel-liver-of-sulphur-extended-life-gel-x-1-fl-oz-30ml.html

Title: Re: Turning a £1 coin black?
Post by: alodg on November 01, 2016, 09:15:26 AM

Interesting, how long does it last?

Is it durable, will the black lacquer survive jangling in my purse?