Digital images of petrology rock thin sections from samples that are referenced in the BGS Petrological Collection Database (Britrocks). Two reference images are being captured for each thin section, one taken in Plane Polarized Light (PPL) and the other in Crossed Polarized Light (XPL). The Britrocks database provides an index to the BGS mineralogical & petrological collection. The computer database covers samples in the UK onshore mapping collection together with worldwide reference minerals and the Museum Reserve collection. The first England and Wales collection sample is from circa 1877, Threshthwaite Comb, Cumbria (collected by the Reverend Clifton Ward). The addition of new samples, transfer of records from registers and updates of existing records is ongoing on a regular basis. Internet access to the database is provided on the BGS web site. Capture of the Scottish Collections began February 2012. Capture of the English and foreign collections began in December 2012.