Old Floor tiles - Quartz? Can I get replacements?

Hi,
We have a washroom, toilet and boiler room which have these hard floor tiles.
The house is a 1930's interwar, its not been renovated, so we presume the tile are original, but might have been added in later, probably no later than the 70's though as most of the house dates back way before then.

As part of our modifications we are installing a new water supply (lead replacement) so part of the floor needs to come up. We wondered if anyone knows what these tiles are called, and if I can get replacements. There's about 15sqm of green and 9sm of white. At a guess the tiles are at least 9mm thick and approx 20cm square.

Thanks guys

Okay - so digging about online this looks like terrazzo? Anyone know if I can polish this with a buffing machine and black pad? and what cutting compound to use?
Cheers

Bets bet would be to find a decent supplier (BnQ and their ilk do not qualify as quality suppliers IMO) of the product and speak to them. If they have a specialist technical team then even better.

They are Terrazzo tiles from the 1960's probably or, as you say, the 1970's.
Instead of digging in the tiled floor, why not abandon the lead supply pipe, & re-route the new water supply? Plastic pipe is just the thing for snaking about.

Plumber is there today, was worried he'd butcher the floor, but he's going to use a core drill in the corner, "should leave 100mm bore hole, nice and neat" - we'll see!
Have ordered a set of burnishing pads from tile doctor (as I have a industrial floor buffer) to clean everything up and then polish. Hoping we can restore it back to its former glory, otherwise its all getting lifted! Was worried there maybe asbestos in the tiles but unlikely now.
Cheers for the feedback, replacements look unlikely so if they do come up they'll maybe pay for the floor pads. Nett neutral .