This question is primarily for @physics-fan3.14 but obviously all opinions are gladly received. I got this from my sister in Vancouver today, she found it in a second hand shop, knew I liked them and paid the princely sum of $3 canadian for it. It was in a 2x2 and marked unc. When you look straight down on it, it resembles a beaten up proof with dark fields. However, when you see the mirror effect it is stunning. The foto shows reflection of 3 2x2's which is much more than any other prooflike piece I own. I know next to nothing about prooflike coins and am curious as to how such a surface can be so reflective.
I'm not sure if you're familiar with the US SMS coins from 1965-1967, but they are very similar to the Canadian prooflike coins. They used business strike dies, but polished them especially to make presentation pieces for collectors. This intentional polishing process of the dies created the mirrors you see.
Here's some good info on the canadian minting process for PL coins . https://www.coincommunity.com/forum/topic.asp?TOPIC_ID=252640 Your could be from a specimen set to .. https://coinsandcanada.com/coins-prices.php?coin=1-dollar-1964&years=1-dollar-1953-1964
