This data sheet was compiled by the Building Research Establishment (BRE). It is based on data from current tests at BRE (2000). The data sheet was compiled in May 2000. The work was carried out by BRE as part of a Partners in Technology Programme funded by the Department of the Environment, Transport and the Regions and Moray Stone Cutters and does not represent an endorsement of the stone by BRE.

General
Clashach Quarry is on the Moray Firth coast. The stone has been quarried since 1846, ceasing in the 1940's at the advent of the Second World War. The present owners have worked the quarry since 1986 and there are good reserves of stone. It is a very hard stone to work and occurs in random sized blocks of size up to 1.8m on bed. It is also a site of special scientific interest with preserved sections of 270 fossilised Permo-Triassic reptilian trackways.

Petrography 
Clashach is a pale yellow buff, non-calcareous, medium grained New Red Sandstone from the Permean age. There is a progressive colour change from the buff to a yellow pink colour across the quarry.

Expected Durability and Performance 
It is important that the results from the individual tests are not viewed in isolation. They should be considered together and compared to the performance of the stone in existing buildings and other uses. Sandstone is traditionally acknowledged as generally being a very durable building and paving stone and has been used extensively in many towns and cities in the UK. Clashach sandstone appears to be a very durable stone that has good resistance to acid rain or air pollution. In addition, the negligible weight loss in the sodium sulphate crystallisation test indicates high resistance to salt damage (for example in coastal locations or from de-icing salts). From the frost test the stone should also have good frost resistance. The compressive and flexural strength of the stone is high for a sandstone. The compressive and flexural strength indicate that the stone should be suitable for use in heavily trafficked areas.

Test Results - Clashach Sandstone

Safety in Use
Slip Resistance (Note 1)	79	Wet. Values > 40 are considered safe.
Abrasion Resistance (Note 1)	Not tested	Values <23.0 are considered suitable for use in heavily trafficked areas
Strength under load
1) Compression(Note 2)	132.3 MPa	Loaded perpendicular to the bedding plane ambient humidity
2) Bending (Note 1)	7.6 MPa	Loaded perpendicular to the bedding plane ambient humidity
	Not tested	Loaded parallel to the bedding plane ambient humidity
Porosity and Water Absorption
1) Porosity (Note 3)	21.4%
2) Saturation Coefficient (Note 3)	0.67
3) Water Absorption	6.9% (by wt)
4) Bulk specific gravity	2084kg/m3
Resistance to Frost
Flexural strength after Freeze/Thaw Test (Note 1)	9.1 MPa	Loaded perpendicular to the bedding plane ambient humidity
Resistance to Salt
Sodium Sulphate Crystallisation Test (Note 3)	-0.80% Mean wt loss
Sodium Sulphate Crystallisation Test (Note 3) (Saturated)	0.0% Mean wt loss
Resistance to Acidity
Acid Immersion Test(Note 4)	Pass

(Test methods Note 1 = prEn1341, Note 2 = prEn 1342, Note 3 = prEn 1341 /BRE 141, Note 4 = BRE 141)

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