Hexagonal prisms of aquamarine embedded in a substrate of flaky muscovite, a common micaceous mineral. Aquamarine is a variety of beryl, the blue to blue-green variety in fact, named after Latin for 'water of the sea'. Minerals of the beryl suite are usually found in pegmatites, complex rock suites formed at great depth. Sample size is 150 mm, provenance the Nagar district of Pakistan.