Petrography is a powerful method of analysis which can determine a wide range of natural stone features and characteristics.
Petrographic Testing Requirements
Petrographic examination is required for all building stone CE /UKCA marked products that are used in UK construction.
Sandberg is UKAS accredited to carry out stone petrographic examination in accordance with BS EN 12407, BS EN 12326-2, ASTM C1721 and ISRM methods.
Microscope large format thin sections are manufactured in-house using a combination of automated systems and manual preparation by our specialist technicians.
Stone petrography is undertaken by Chartered Geologists using research-grade Zeiss and Leica petrological photomicroscopes, employing magnifications up to x500, fitted with in-built reflected light and fluorescence settings.
A standard petrographic report typically includes comments, where applicable, on the following:
- Classification to BS EN 12440
- Macroscopic and microscopic description
- Constituent composition (with estimated volumes)
- Structure and texture
- Grain size
- Porosity
- Compaction
- Microcracking
- Veins
- Stylolites
- Weathering condition
- Potential deleterious constituents (e.g. iron sulfide, swelling clay minerals)
Further Testing
Where necessary, petrographic examinations are supported with scanning electron microscopy using an in-house Hitachi SEM with an Oxford Instruments analytical system, which allows, for instance, the composition of clay-grade material to be determined.
