NEW YORK STATE BLUESTONE INDUSTRY STANDARDS AND SPECIFICATIONS
New York State Bluestone is a commercial name for a distinctive variety of sandstone or wackestone found only in South-Central New York State and North-Eastern Pennsylvania. The stone is a strongly indurate (cemented) stone of various colors, which most typically splits easily into thin smooth slabs (natural cleft, flagstone). Bluestone consists primarily of feldspar, quartz, phyllosilicates, and other accessory minerals held together by a strong siliceous cement.
Natural Cleft Bluestone
Color: Full range natural occurring with various shades of blue, gray, green, buff and lilac with random surface varying from blue to brown and gold.
BLUE STONE DIMENSIONAL TOLERANCES
Thickness tolerance varies dependent on quarry conditions.
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5/8″ Nominal,+ 1/4″ and 1/8″
1″ Nominal,+/- 1/4″
1-1/2″ Nominal,+ 3/4″ and 1/4″
2″ Nominal, =/- 1/2″
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Quarry Cut, Length/Width/Squareness, +/- 1/4″
Shop Cut, Length/Width/Squareness, +/- 1/8″
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Exposed Edge Dimensions
Quarry Cut, Height, +/- 1/4″
Shop Cut, Height, +/- 1/8″
Surface variation not to exceed =/-1/8″ in each square feet of exposed edge.
Allow 1 1/2″ bed for setting.
Allow 3/4″ bed setting for treads, coping and sills.
Backs of Stones
Backs of all pieces may be natural or sawn.
Backs of paving may not vary more than 1/2″ in 12″.
Backs of treads, coping and sills may not be more than 1/2″ in the bed.