Where can I trade dark energy crystals?

I'm curious, could you please enlighten me on where exactly one might engage in the trading of these so-called "dark energy crystals"? Are there specific platforms or marketplaces that cater to such unconventional exchanges? And furthermore, what exactly are these dark energy crystals, and what kind of value do they hold in the realm of cryptocurrency and finance? I'm eager to learn more about this intriguing topic.