Black Galaxy

How the grade is decided

Premium, often sold as Star, carries small, tight, evenly scattered bronze flecks across the whole slab with no clustering and no pale patches. Standard allows the density to vary noticeably between one end of a slab and the other. Commercial permits visible clustering, larger flecks and the occasional grey or quartz patch.

Because that grading is visual and the belt is small, two slabs sold at the same grade by different suppliers can look quite different. Ask for photographs of the actual bundle in daylight rather than a catalogue swatch, and if the job runs across more than one bundle, ask whether they were cut from the same block.

Finish, and how it behaves

Polished gives the deepest black and makes the bronze read as metal. It also shows fingerprints and water marks more readily than almost any other stone, which is worth knowing before it goes on a kitchen island in daily use. Honed drops the reflection and mutes the flecks to a soft bronze. Leathered hides marks best, and is the usual answer when a client wants black without the upkeep.

What to specify when you order

• The grade in words as well as by name: "small even flecks, no clustering" is clearer than "Premium"
• Thickness, and whether edges are polished by us or on site
• Whether slabs must be sequenced from one block for a continuous run
• Finish, and for polished work the gloss level you expect
• Packing, and the crate weights your site can lift