Japanese researchers have discovered record gold concentrations - and in a place few would think to look: an underwater volcano. The deposit lies in the Higashi-Aogashima hydrothermal field, inside a submerged volcanic crater about 350 kilometres south of Tokyo. What makes the find special is that it contains both visible gold grains and so-called "invisible gold" - nanoparticles and single gold atoms trapped in the crystal structure of pyrite.

Pyrite is known as "fool's gold" - a mineral that shines like gold and for centuries lured miners into thinking they had struck riches where there were none. But this time the story is reversed. According to the authors of the study, published in the scientific journal Scientific Reports, this pyrite contains the highest gold concentration on the planet. In other words, fool's gold this time hides the real thing.

The deposit was actually discovered back in 2015, but the new analysis now reveals just how rich it is. And here begins the second, quieter part of the story - the one that rarely makes the headlines. The discovery reignites the debate over deep-sea mining, which many consider an ecological disaster. Japan continues to push for commercial underwater mining, despite international moratoriums and calls for caution.

History advises modesty. Papua New Guinea's underwater mining project collapsed in 2012 and cost around 85 million dollars - money thrown into the sea, literally. The question this discovery leaves behind is not whether there is gold down there; there is, and plenty of it. The question is whether it is worth destroying an untouched underwater world to extract it. And that is a decision that, as usual, will be made by those who will not live beside that sea.