Sample Formats
The fundamental format types are Hand Specimen (code HS), Rock Slab (code RS), Loose Powder (code LP) and Powder Pellet (code PP). These are described below. Additional format types are Fusion Bead (code FB, homogenised material vitrified and pressed into disks and usually produced in association with Power Pellets), and Thin Section (code TS, rock slices used for optical mineralogy/petrology, electron microprobe and SEM).
Hand Specimens maintain natural features, form and texture (fresh and weathered) so are field representative. Ideal size: Commonly ~15 cm x ~15 cm but depends on heterogeneity, grain size and application (for example geotechnical studies require more resource than analytical, non-destructive, experiments). Residual pieces can be used to produce rock slabs, pellets and powders. Ideal surfaces: Fresh (natural and sawn), weathered. These can be on single sample or a number of samples. Distinguishing features should be retained (i.e. phenocrysts, veins, cryptoendoliths, etc etc) |
Rock Slabs are geometrically constrained but otherwise mineralogically/petrologically intact. Thick sections and chips (from the manufacture of thin sections) fall under this category. Ideal size: 5cm x 5cm x 1cm but depends on ability of material to be sawn and remain fully intact. Quantity will depend on grain size, heterogeneity, etc Ideal surfaces: Sawn both sides or sawn side plus polished side. |
Powder Pellet (homogenised material compressed into a standard form) and Loose Powder (either natural (i.e. "as is") or homogenised material) Ideal size (PP): ~35 mm diameter and ~5 mm thick. Ideal quantity (LP): Several hundred grams of residual material as powder or crushate required to reproduce pellets. |
