Mineral Ores are a type of Cargo consisting of minerals used as food in the Dine-o-Mat.
They can only be obtained via Trade, with the Salt Hogs being the primary sellers. The Karmarama will happily purchase any spare ore at a high price. If you have no Mineral Ores at all, Arona Daal will have at least one crate available.
Note: unlike other items, researchers will not automatically research improvements of Mineral ores, they will only do so when provided with crates on the Analyser. As Mineral ores can not be manufactured, improvements have no effect, so this is only an issue if you want to fill out the research tree.