grease and toning

[seankedahan]

Greetings, recently i have encountered a question regarding the grease and toning. In my mind for silver it is due to silver sulphide. However, there are different opinions that grease will cause some kind of different toning pattern. I found out that the grease has additives to let the grease stick to the die longer which may contain sulphide.

How does the imparted grease from die to coin affect the toning of a coin exactly?

What is the substance in grease that can cause or accelerate the toning of the coin?

If there is no environmental other than grease will it tones as well? 

How does the toning caused by grease different from those environmental-caused toning?

Thank you.

[Conder101]

All planchets have a light film of oil on them to help them move through the feeding mechanisms without sticking.  The thickness of that film can affect the rate of toning because it tends to protect the metal from the atmosphere.  The thickness of that layer on the struck coins will not be uniform.

Also typically when we talk about "grease" on coins, struck through grease etc.  It isn't actually grease we are talking about.  It is lubricating oil with dirt, dust, metal dust and filings etc in it.

[seankedahan]

2 hours ago, Conder101 said:

All planchets have a light film of oil on them to help them move through the feeding mechanisms without sticking.  The thickness of that film can affect the rate of toning because it tends to protect the metal from the atmosphere.  The thickness of that layer on the struck coins will not be uniform.

Also typically when we talk about "grease" on coins, struck through grease etc.  It isn't actually grease we are talking about.  It is lubricating oil with dirt, dust, metal dust and filings etc in it.

Does the ingredient of the oil can cause toning?