A shungite-and-cement plaster you trowel on the wall measured -10 to -30 dB of EMF shielding from 0.5 to 18 GHz

The short version

We have threads on shungite EMF plates and on shungite composites. Here's the most practical version of the idea: a plain plaster - shungite powder mixed into cement - that you apply to a wall like any render, measured for how much radio-frequency signal it blocks. The answer is a usable amount, across the whole band that phones, Wi-Fi and microwave links live in.

What they did

A group at the Belarusian State University of Informatics and Radioelectronics built the coating and measured its transmission:

"отделочные материалы на основе шунгита характеризуются значениями коэффициентов передачи от -10 дБ до -30 дБ в частотном диапазоне 0,5-18 ГГц"
"shungite-based finishing materials show transmission coefficients of -10 dB to -30 dB across the 0.5-18 GHz frequency range."

The recipe and the result

- Mix: 40% shungite, 25% Portland cement (PC 500 D20), 35% water
- Applied as a 4 mm layer
- Shielding: -10 dB to -30 dB over 0.5-18 GHz

In plain terms, -10 dB means about 90% of the signal power is stopped; -30 dB means about 99.9%. A 4 mm trowelled-on coat, no special equipment, landing somewhere in that range depending on frequency. That covers FM/TV (0.5 GHz), mobile bands, 2.4/5 GHz Wi-Fi, and on up to 18 GHz.

Why it's worth knowing

Most "shungite for EMF" talk is about pyramids and plates near a device. This is the building-material version: a wall finish with a measured shielding spec from a university radio-engineering lab. It's the difference between an ornament and a construction material.

Sources

- Makhmud M.Sh., Belousova E.S., Kazeka A.A., Prudnik A.M. (2014), "Отделочный материал на основе шунгита для защиты биологических объектов от электромагнитных полей", Доклады БГУИР: cyberleninka.ru