Tono's Famous Stone: Granite Porphyry, 3 Types of Square Shapes, Made with Ancient Stone Tools

Tono's Famous Stone - Granite Porphyry (Amphibole) - Ancient Stone Tool Manufacturing
Three types of square shapes
Tono's Famous Stone Granite Porphyry (Amphibole) - Ancient Stone Tool Manufacturing

This is a precious stone said to have far-infrared effects, with purifying, sterilizing, and deodorizing properties.
Place it near plants
Use it as a power stone.

Sizes
45×45×15mm
60×60×60mm
70×70×10mm

Purchased about 40 years ago through a transaction with K.K. Kodaiseki. This is leftover stock from when the company went out of business 3 years ago. Although unused, there was some dust from storage.
The stones have been washed and cleaned.
There are many others, but the two square types being exhibited this time are sizes not listed in the brochure. They were previously sold for grilling food on top of Nambu cast ironware.
The 60mm size is the same as the size of Agemono Karatto (a frying accessory).
They come without a box. There are 3 brochures remaining, and as I wish to keep them, a of the brochure will be included.
Multiple items can be purchased together, so please inquire.

Thank you for looking.