Correct iron ii sulphate (copperas)?

[Russy69]

Hi all,
Firstly I’d like to say thank you to all the experienced people who help everyone on this forum with their knowledge. I’ve been a member for a while, but this is my first post. The forum has been invaluable part of my learning, and when I first started and realised how much more I needed to learn. I then spent another 18 months reading hokes and this forum, before even considering dropping and melting my first little button (chuffed to bits).
This was especially hard at the start as I live in uk and no access to nitric or sulphuric acid, however this may have helped by having to try and learn the ‘science’ behind it for alternative methods.
Introduction out of the way (sorry it’s long)

My question is about copperas. I’ve used it in the past as 1 method of precipitation.
The green crystals are made into a brownish solution, then activated with hcl, solution turns green, then it’s filtered prior addition.
However,
I’ve just purchased some more iron ii sulphate (sulfate) and it has the characteristic green crystals, but when I prepare it, the solution stays the typical green colour of the crystals, like it’s already been activated with hcl? It’s at this point ive now stopped and spent a few days researching, but I’m obviously missing something. (Hence my first post
So, basically the question is.

When preparing My copperas solution in water, it is green from the start and not the usual brown prior to activation with hcl. What am I missing??

Thanks again in advance and I’ll carry on researching and update the post if I find the answer.

(It’s going to be something silly ive missed I’m sure) pic below of my first button as well as pic of some metallic gold that precipitated, as I’m seen that mentioned a few times here.

 

[upcyclist]

Personally, I bought some food-quality (wine, actually) copperas off Amazon, and I don't make a solution at all. I sprinkle it directly into my gold chloride solution (after driving off excess nitric).

 

[butcher]

Fresh copperas is green in solution or crystalized, as the crystals are dried or lack the dampness of acid in air the crystals will oxidize the green crystals will turn brown, and further oxidized then will turn white as an oxidized powder of iron no longer called copperas, ferrous sulfate or (iron II sulfate),and no longer suitable to precipitate gold from solution.

 

[Russy69]

Thanks you both for the info I’ll check the wine section too.
it’s a brand new bag so still fresh and green, it is lab grade not the lawn fertiliser type I believe. Havent tried using it dry, contemplated lots though , except as an alternative to stannous as a test. I thought small amount of metallic iron was produced hence the filtering, but it is a minute amount. Sadly I can’t get nitric acid in U.K, so it’s poormans with a nitrate, an sulphamic to denox. We can’t even get sulphuric acid as that was band a while back too.
So it seems if I’m making a solution, and it’s already green, then there is no need to add a splash of hcl to “activate”
I’ll get 3 small samples of aucl and try itin solution and in solution with hcl.

Thank you again
Andrew

 

[Geo]

The brown is iron oxide. When you add HCl, it creates ferrous chloride. Same color in solution as ferrous sulfate but will not precipitate gold. Next time add dilute sulfuric acid. It will redissolve the iron oxide back into green iron sulfate solution that will drop gold.
I make my own by dissolving rusty nails is dilute sulfuric acid and filtering while cool. It works very well and is always freshly made.