The Diatoms Herbarium is an ancillary collection in the Diatoms Collections at the Natural History Museum. It comprises processed and unprocessed samples preserved dried directly onto paper, glass or mica sheets and stored in paper packets mounted on standard herbarium sheets. Each herbarium sheet may contain one to several of these packets. This collection is rich in samples containing type material, including many by F. T. Kützing and W. Smith, as well as historical exsiccate sets such as G.L. Rabenhorst's Algarum europaearum Exsiccatarum and Ardissone's Erbario Critogammico Italiano and represent a valuable resource for diatoms taxonomy investigations using modern techniques such as Scanning Electron Microscopy.

This dataset provides a complete catalogue of the Diatom Herbarium. Each specimen has been databased to capture, minimally, its registration number (barcode) and the 'filed as' name, which may or may not be the currently accepted name. Most of these specimens have images associated with them, such as a photograph of the herbarium sheet.