Tunisian black marble

This has been rather a frustrating day. I have started to work this lovely block of marble. A marble I have never used before. As soon as I started to try and cut it however my blade went blunt. In horror I rang my friend Jonathan Loxley who bought a block at the same time and he was mystified by my problem saying that “it works quite well”. I put the block back in the field and went in for lunch, fed up. After lunch I went and visited my supplier of blades who told me that the blade was not ruined (phew) but ‘blinded’ or ‘clogged’ by the stone. He sold me a new blade which he told me would not clog. I made much better progress in the latter half of the day on a new ring. Although the marble here looks quite white, it actually polishes almost black with strong white veining.