Excel spreadsheet that allows for fast plotting onto a TAS (total alkali silica) diagram for use in naming your volcanic rock by composition. Created using coordinates as given in Le Maitre et al (2002). Version 3.0 New version by Cédric Gouard. Significant improvements and new features! Logic based on rock composition will now classify your rock type even further than the fields on the TAS diagram. For example, a trachybasalt may be further identified as a hawaiite or potassic trachybasalt; a basaltic trachyandesite may be further identified as a mugearite or shoshonite. The TAS diagram is now drawn in a more sensible way from formulae, and overall user friendliness is improved.

{"references": ["Le Maitre et al (2002)"]}