The so-called bian stone has grade refers to whether the natural stone used to make bian stone has grade. All natural gemstones have quality grade differences, just like jadeite, jadeite and agate have quality grade differences and huge price differences. Stone made of different raw materials must also have different quality grades. According to the strange stone grading standards issued by the Strange Stone Committee of the Asian Jewelry Federation and the Strange Stone Expert Committee of the Chinese Geriatric Health Care Medical Research Association, strange stones can be divided into:

1. According to the number of ultrasonic pulse events caused by the rubbing of bian stone against human body, bian stone is divided into three grades: Grade A, >; 3,000 times; Grade b, > 2500 times; Class c, > 2000 times

2. According to the penetration rate of ultrasonic wave generated by bian stone to human body, bian stone is divided into three grades: A grade, > 90%, B grade, > 75%, C grade, > 60%;

3. According to the maximum wavelength of radiation infrared spectrum bandwidth, ochre is divided into three grades: Grade A, >15μ m; Grade b, >14μ m; Class c, >13μ m.

4. According to the intensity of infrared radiation, ochre can be divided into three grades: Grade A, 9.9× 10-4 (w/cm2 Sr um), Grade B, 8×10-4 (w/cm2 srum) and Grade C >: 7×/kloc-0.

5. Stone can be divided into three grades according to the grain size of mineral crystals: Grade I, grain size.

On this basis, the classification standard of comprehensive grade of bian stone is given. Stone is divided into five grades: A, 2A, 3A, 4A, 5A and * * *.

Is the ancient recorded bian stone the same as the modern bian stone?

The bian stone recorded in ancient books can be called the narrow sense bian stone, that is, the pumice formed by the second variation of the ancient Surabaya coast in Shandong Province, that is, the Sibin pumice, which the locals call the Four Lunatone. This kind of stone is scarce, and it reappears in the world after two thousand years of snow storage through high-tech means. Modern bian Shi refers to bian Shi in a broad sense. Stone * * * is divided into five grades. As long as the stone is harmless to the human body and has some physical characteristics beneficial to the human body, it can be called a stone. After a large number of authoritative experiments, only the banks of Sishui River Basin in Shandong Province, China have found good stones meeting the standards of 5A and 3A. Other provinces and cities have not found it.

How to tell which businesses in Sibin, Shandong sell stone?

As a Bian Shi, you must:

1, test report of major elements, trace elements and rare earth elements;

2, radioactive and harmful substances test report;

3, far infrared band, peak, intensity test report;

4, ultrasonic and ultrasonic permeability and vibration frequency test report;

5, mineral crystal size (rock ore identification) test report.

These tests are the most powerful evidence to directly judge whether it can be used as bian stone or not. Consumers must read the test reports in these aspects before buying bian stone products. Some businesses use the testing reports and so-called testing reports of home improvement materials made by some small testing companies to fool consumers. You need to polish your eyes to distinguish them.