I Have Spare Tiles Venis tiles 20x33- unknown type

[oli_barrow]

Hopefully I'm posting in the right place. I inherited these with a house purchase, does anyone know what they are, and if they would be of use to anyone? They measure 20 x 33cm. I have around 60 in total, with another 10 or so in a very similar effect, but more of a grey effect. TIA, Oli