I don't know why this exists but my grandmother gave it to me and I had it for years before I really looked at the coin
Could I ask what the House of Rio means? The only thing I get from google is real estate listings in Rio. Which wouldn't be too bad if they would at least show a hot real estate lady with them.
Well, don't know if it's this what you are asking, but the House of Rio must be the Rio de Janeiro Mint (Casa da Moeda do Rio, or House of Coin of Rio). That's why you can see the "R" on the colonial coins. There were another Mints during portuguese colonial times like: Bahia, Cuiaba, Minas Gerais and Pernambuco.
Thankyou for the info. I found that motiff on images of other Brazilian coins. Is it or was it some kind of Rio Mint crest?
Which motive are you referring to? The main difference between the Mints is just the letter at the center: R for Rio, C for Cuiaba, M for Minas Gerais, B for Bahia and P for Pernambuco. For the most part the coins from colonial period carry the Portuguese coat of arms, the armillary sphere (both still present in today's Portuguese flag) and the Order of Christ (a Templar order in Portugal) cross.