the mutual that reblogged 30 pictures of Angkor

In general, the visual identity of Cambodian coin changed all the time under the French rule. There were even the coins with holes in the middle at some point:

...or even just these mysterious rectangles

Spanish-American dollar (or peso) was also in wide use, just like in many other countries around the world in 19th century.

The name of the modern currency - riel - likely comes from the name of real coins, 8 pieces of which made up a single peso.

500 riel coin

Small coin of 10 sen. Subunits of riel are not currently used.

Left: souvenir coin with a dancing Apsara and kbach khmer ornament, 3000 riel. Right: possibly a pattern coin or even an unused design?

Riel in general is mostly used for small purchases, businesses in Cambodia will gladly accept US dollars without the need to exchange.

Coins in Cambodia seem to have been known since the Funan civilisation (I-VII century AD), but not in wide use. Cowry shells were preferred, although some coins were found around the city of Angkor - they likely came there through foreign trade

Foreign coins found in Angkor above

Coins were not mass produced in Cambodia up until the Longvek period (most of 16th century), long after the fall of Angkor, using imported European technology.

First coins were very basic and all have very similar designs without much variation. Later, after Siamese invasion, when Cambodia fell under the influence of Ayutthaya, coins with more intricate designs started to appear. Most often they depicted mythical animals or flowers.

First coins in Cambodia were called tical. It was a common name for a coin in modern day Laos, Cambodia and Thailand. Siamese coins (including baht) were also not uncommon - Thai currency is still accepted in some places in Cambodia

Cowry shells and Thai tical on a French illustration.

Under the French protectorate, Cambodia kept tical for some time; the quality of the print generally improved.

Most French protectorate tical designs also feature mythical creatures, but portraits of royals and reliefs of palaces and temples can be seen on later coins.

Cambodian Franc was introduced at the last quarter of XIX century and was designed after and equal to the French Franc at its rate.

This Franc features king Norodom - the first king during the protectorate and the founder of the current ruling dynasty.

Only 10 years after its introduction it was replaced by a piastre with a more generic, Western design and was in use until Cambodia gained independence.