Mineral Cup: from tearoom banter to global competition

Abstract Mineral Cup is an annual global volunteer-run competition to determine the most popular mineral, decided by public voting and played out mainly on social media. Over nine years of Mineral Cup, nine distinct minerals or mineral groups have been crowned champion, in chronological order: olivine, garnet, ice, magnetite, quetzalcoatlite, fluorite, zircon, rhodochrosite and kyanite. Participants in Mineral Cup can vote for minerals for any reason, ranging from scientific and often esoteric to aesthetic. Factors influencing voting include name or nickname, colour, striking appearance, utility, unusual characteristics, cultural impact, and fun facts. Mineral Cup has a global reach, with over 30,000 voters a year in 2018–2025 encompassing voters from over 100 countries per year. The popular knockout format of Mineral Cup could also be used in a wider range of geoscience competitions, and in late 2025 the first such instance of a spin-off competition (Ore Cup) was held. In the context of declining enrolments in geoscience degrees, we discuss Mineral Cup as a potential tool to promote the joy of mineralogy widely, including to audiences that may otherwise have limited or no exposure to geoscience. Finally, we provide an outline of future directions of Mineral Cup, the reach of which as an entity is currently limited by volunteer time and availability in much the same way as professional society activities are limited by the availability of their members.