Video B.1: M4 LA-ICP-MS trace element accessory mineral maps, Grunnes steatite quarry, sample RC180410c In these maps, the darkest purple colours indicate very low (or absent) concentrations of the element for that map. With increasing concentrations of that element, the colour changes across the spectrum from purple through blue, with the brightest cyan tones indicating "very high" concentrations of that element, with respect to the total amounts of that element measured for each sample. For the trace elements the highest concentrations may be only a few ppm, yet still be represented by the bright blue shades for one or more crystals, in contrast to the total absence (very dark purple to black), or much lower levels (brighter purple) of the other crystals analysed. Therefore, the below list of element concentration maps included in this film also indicates which of these elements are the major elements (dominate) of a given crystal, and which are trace elements. The video sequence (approximate times) is: 0:00 The location of Grunnes quarry 0:09 hand sample RC180410c from that quarry 0:12 reflected light image of a pyrite crystal, its pentlandite inclusions, a nearby ilmenite crystal, and their surrounding matrix grains that were analysed as map M4, 0:14 S (dominate in the pyrite crystal and pentlandite inclusions) 0:17 Co (trace amounts in the pentlandite inclusions) 0:20 Fe (dominate in the in the pyrite crystal and pentlandite inclusions) 0:21Ti (dominate in the ilmenite grain) 0:24 Cr (trace amounts in the chlorite) 0:26 Mn (trace amounts in the ilmenite and amphibole) 0:28 Ni (trace amounts in the pentlandite inclusions) 0:30 V (trace amounts in the chlorite) 0:33 Ag (trace amounts in only the smaller of the two pentlandite inclusions) 0:35 The reflected light image of the crystals (repeated) 0:36 A collage of all of the above trace element maps surrounding the reflected light image, plus the addition of maps for Al, and Y, as these are elements which also feature in the minerals present.