Azurite Nodule/Geode
One of the most spectacular nodules that show a rather thunderegg-like split - but instead of rhyolite, they are formed of azurite. They tend to be small - pushing the limits of my scanner in this case, but the vivid blue really make them stand out.
2cm
Countries:
USA - Canada - Alaska - Mexico - Argentina - Peru - France - Germany - UK - Poland - Greece - Turkey - Romania - Bulgaria - Slovakia - Kazakhstan - Uzbekistan - Russia - Japan - Ethiopia - Iran - Australia - Unknown