Professor Barber found that the teeth contain a hard mineral known as goethite, which forms in the limpet as it grows. (sciencedaily.com)
But a range of other rocks appear in the archaeological record, from the yellow ochre goethite to the often - dramatic specular hematite, sometimes called specularite. (discovermagazine.com)
We discovered that the fibres of goethite are just the right size to make up a resilient composite structure. (sciencedaily.com)