Coloured gemstones are small, valuable, and easy to transport—making them attractive to smugglers. Around the world, coloured gemstones are often mined by artisanal miners working informally, without regulation. This creates conditions where armed groups can exploit mining communities and opportunities for illicit trade. At mines where armed forces are present there are instances of human rights abuses, dangerous working conditions, child labour, and gender-based violence. While the link between coloured gemstones and conflict financing is not as well reported as for other minerals, there are many instances where armed groups or governments have exploited gemstones for their own gain, such as Cambodia’s Khmer Rouge and sapphires and Myanmar’s military and jade. The artisanal mining of coloured gemstones is linked to extensive environmental damage, including water pollution and deforestation. Similar to experiences with other minerals, countries around the world may have an abundance of gemstones but their monetary value is rarely translated to enduring benefits for miners and their communities. Most of the profit from gemstones is obtained after they are exported and have been cut and polished.