How Do I Tell If My Loonie Is Bronze Or Nickel-Bronze?

I didn't know they made anything out of pure bronze? Nickel will be magnetic since it gets work hardened when it is hit by the dies.

And welcome to the forum !

My knowledge of modern coinage is very lacking... but I do have a knowledge of electroplating.

Interesting data, I didn't realize we were just talking about the plating. They could in fact plate with bronze if they used copper as an intermediate layer and still use a cyanide free process, but that adds yet another step in the plating process that really isn't necessary. While cyanides are common in many types of plating they are primarily used for consistent anode corrosion and it isn't strictly required IF there is an intermediate layer that has strong attraction to both metals (copper has strong attraction to nickel and bronze).

Basically I'm saying bronze plating can be done cyanide free but it either needs additional plating steps or a not cost effective plating bath. The composition of bronze used for the loonies is also known as alpha bronze since it has a very low percentage of tin and this makes it less yellow in colour that normal bronze with it's usual 40%tin content. Brass give off zinc oxides as it forms it patinas... you can see this as a whiteish hue, it should stick to inner edges of the protected raised areas of the lettering on a coin.

What I learned: Loonies can be brass or bronze plated. thanks!

don't you love coin collecting: we get to learn metallurgy, as well as history, geography, art, politics ...

It's naturally ferromagnetic on it's own without work hardening, but once it's struck at that force it's overall plasticity and magnetic properties change significantly. If you get a raw nickel pellet and hold a magnet to it before and after it's struck you can feel the difference, the same as you can feel the difference in attraction with a steel plated five cent piece and a pure nickel one, the steel being much more attracted and requiring more force to pull it off. The same is true of nickel, a weak attraction in unhardened form moves to a strong attraction in hardened form.

The difference in hardness of the nickel before it's struck and after it's struck is incredible, it goes from low 80's on the Brinell Hardness (HB) to around 140's.

One of the best places to see work hardening affecting magnetism is on a beer keg made of stainless steel, the sides usually won't attract a magnet strong enough to make it stick on it's own (but it's still ferromagnetic) yet the rolled rim at the top which is the same material is work hardened and will make a magnet stick under it's own attraction.

This is one of the best examples of work hardening affecting magnetism I can give that can be tested by someone without instruments.

Yes, the new loonies tone very UGLY-ly. Is that a word? I always wondered why they were different and why they didn't look like 1987s or even 2004s. I've noticed this especially on commemoratives such as the 2008 Lucky Loonie and the 2009 Montreal Canadiens. I'm sure the 2010 Inukshuk Loonie and 2010 Navy Loonie do the same thing but I've only seen those as BU/MS.