The teeming life and beauty of the coral reef is the spotlight of the Mint of Poland’s latest coin

Given how popular nature themed coins are, it’s pretty surprising that the world’s coral reefs are not more common as a subject. The most recent was the very impressive two-kilogram antique-finished coin released by the Perth Mint, a giant piece with a cool style that showcased the Great Barrier Reef. The Mint of Poland have issued a new coin of their own.

A two-ounce, antiqued silver coin with lashings of high-relief, it’s an attractive composition, showing off the reef structure itself, as well as some of the vast biodiversity that inhabits it. We like how the application of colour is restrained, although not as well chosen as could be, but that’s a minor point.

In a page taken from MDM’s playbook, the use of a translucent blue resin to infill the coins deepest parts is a great touch, especially as it covers an area so close to the rim. The mint has taken great pains to convey a sense of depth with scaled elements in the background. The main attraction, the antiqued high-relief central section, is composed really well, as is the raised border, which could have been a simple thing, but is fully incorporated into the design instead.

It’s a very plain obverse, sadly not one of this mints customised efforts, but the presentation looks okay. We still like those latex-skin display frames, and while we can’t see it on the official images, we suspect the COA is printed on the frame insert, which is fine. Capped at 500 pieces, we like this one a lot, and it’s proof that the mint can do more with this format than just myths and legends themed coins. More please. Available to order now.


A coral reef is an underwater ecosystem characterised by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.

Coral belongs to the class Anthozoa in the animal phylum Cnidaria, which includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons that support and protect the coral. Most reefs grow best in warm, shallow, clear, sunny and agitated water. Coral reefs first appeared 485 million years ago, at the dawn of the Early Ordovician, displacing the microbial and sponge reefs of the Cambrian.

Sometimes called rainforests of the sea, shallow coral reefs form some of Earth’s most diverse ecosystems. They occupy less than 0.1% of the world’s ocean area, about half the area of France, yet they provide a home for at least 25% of all marine species,including fish, mollusks, worms, crustaceans, echinoderms, sponges, tunicates and other cnidarians. Coral reefs flourish in ocean waters that provide few nutrients. They are most commonly found at shallow depths in tropical waters, but deep water and cold water coral reefs exist on smaller scales in other areas.

Most coral reefs were formed after the Last Glacial Period when melting ice caused sea level to rise and flood continental shelves. Most coral reefs are less than 10,000 years old. As communities established themselves, the reefs grew upwards, pacing rising sea levels. Reefs that rose too slowly could become drowned, without sufficient light. Coral reefs are found in the deep sea away from continental shelves, around oceanic islands and atolls. The majority of these islands are volcanic in origin. Others have tectonic origins where plate movements lifted the deep ocean floor.

Healthy tropical coral reefs grow horizontally from 1 to 3 cm per year, and grow vertically anywhere from 1 to 25 cm per year; however, they grow only at depths shallower than 150 m because of their need for sunlight, and cannot grow above sea level.

Coral reefs form some of the world’s most productive ecosystems, providing complex and varied marine habitats that support a wide range of other organisms. Fringing reefs just below low tide level have a mutually beneficial relationship with mangrove forests at high tide level and sea grass meadows in between: the reefs protect the mangroves and seagrass from strong currents and waves that would damage them or erode the sediments in which they are rooted, while the mangroves and sea grass protect the coral from large influxes of silt, fresh water and pollutants. This level of variety in the environment benefits many coral reef animals, which, for example, may feed in the sea grass and use the reefs for protection or breeding.

Reefs are home to a variety of animals, including fish, seabirds, sponges, cnidarians (which includes some types of corals and jellyfish), worms, crustaceans (including shrimp, cleaner shrimp, spiny lobsters and crabs), mollusks (including cephalopods), echinoderms (including starfish, sea urchins and sea cucumbers), sea squirts, sea turtles and sea snakes. Aside from humans, mammals are rare on coral reefs, with visiting cetaceans such as dolphins the main exception. A few species feed directly on corals, while others graze on algae on the reef. Reef biomass is positively related to species diversity. (Wikipedia)

COMPOSITION 0.999 silver
WEIGHT 62.2 grams
FINISH Antique
MODIFICATIONS High-relief, Colour, Resin infill
BOX / C.O.A. Yes / Yes

This article uses material from the Wikipedia article “CORAL REEF“, which is released under the Creative Commons Attribution-Share-Alike License 3.0