Japanese sandstone coffee service, 80s

I offer a coffee service made in japan in the 80s (signed farmer sandstone, made in japan). It consists of 6 coffee cups and their saucers, a sugar bowl and a coffee maker. It's in perfect condition. The coffee maker is 22 cm high and has a diameter of 8.5 cm and weighs about 550 grams. The cups are 6.5 cm high and between 4.5 and 5 cm in diameter and their saucers are 8 cm in diameter and weigh about 200 grams together.