These are beautiful gold coins that South Africa issued between 1961 and 1983. The front (obverse) shows the likeness of Jan van Riebeeck, the Dutch colonial administrator of Cape Town who many regard as the founder of South Africa, and the back (reverse) shows the famous South African springbok antelope.
These coins are worth their weight in gold:
1 RAND: 0.1177 troy ounces gold
2 RAND: 0.2355 ounces
To find their value, multiply the current price of gold by the gold content. For instance, today's gold price is $1231 US dollars per troy ounce (look it up, tomorrow it will be different), so a 2 rand coin is worth 0.2355 x 1231 = $290.
Like most modern gold coins, these are worth gold value and nothing more. Government mints try to spiff them up with fancy packaging and impressive documentation ('certificates of authenticity' and the like), but, alas, these trappings add nothing to value. Proof coins, with mirror-like surfaces, are made only for collectors and look really cool. Premiums for proof coins are almost non-existent, adding, perhaps, a few dollars to value.