Frosting lustre on circulation 2017 5p?

[Lotad 7]

I noticed that some 2017 5p's I received in change looked odd and had a different lustre to the regular ones, I thought they were proofs at first. The coin on the left is normal, the one on the right has the odd lustre.

What do you think would cause this?

[craigy 363]

i'm sure i had some correspondence with the royal mint about this i noticed on a 20p and they said it was a new technique they were trying or something, also has some frosted proof like 5p's as well in my change. also the brilliant uncirculated coins are now coming out with a deep proof like appearance 

[Sword 1,541]

  On 2/5/2019 at 10:34 AM, craigy said:

i'm sure i had some correspondence with the royal mint about this i noticed on a 20p and they said it was a new technique they were trying or something, also has some frosted proof like 5p's as well in my change. also the brilliant uncirculated coins are now coming out with a deep proof like appearance 

I personally think that the shiny non frosted version is better for circulating coins as the surface marks would be less obvious. Also shiny coins looks "newer" and nicer to receive in change.

[Mr T 191]

I would have guessed something like a new die finish - I guess that's what craigy is getting at.

[Peckris 2 2,216]

to me, the coin on the RIGHT is the normal one compared to the one on  the left.