# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/Dct34vVSAOc
- **Gondola URL:** https://gondola.cc/posts/70003068-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/151b8ff189.jpg
- **Posted:** 2026-08-31T19:50:55.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

A stone soft enough to shape with a woodworking rasp, sitting inside a firebox at eight hundred degrees. Finnish soapstone does both.

The Finnish name is vuolukivi, literally carving stone. Most of it comes from Nunnanlahti in Juuka and from the Kainuu region, and Finland holds an estimated seventy per cent of Europe’s soapstone reserves. What makes the rock unusual is the mineral split.

- Talc, roughly forty five per cent
- Magnesite, roughly forty five per cent
- Chlorite and oxides making up the remainder

Talc is the softest mineral on the Mohs scale, a one. Its structure is a stack of silicate sheets held together only by weak van der Waals forces, so the layers shear past one another under a fingernail. That is why soapstone feels greasy and why a rasp bites into it like hardwood.

Magnesite is the counterweight. At Mohs three and a half to four, the carbonate grains lock those talc plates into a dense, coherent mass. Brazilian and African carving stones can run seventy per cent talc and cut like cheese. Finnish stone pushes back against the blade, holds a crisp arris and does not crumble under fine detail.

The thermal figures explain the fireplaces:

- Thermal conductivity around 6.4 W/m K, five to eight times that of firebrick
- Specific heat capacity approximately 0.98 kJ/kg K
- Density near 2,980 kg/m3

Multiply the last two and a cubic metre soaks up roughly 2.9 megajoules for every degree of temperature rise. A soapstone heater takes one short, hot burn and radiates it back across the following twelve to twenty four hours.

Carvers work with the foliation, never against it. The faint banding in a slab is the fabric left behind by the deformation that built the rock, and it decides where the tool runs clean and where it tears.

Soft enough to carve, dense enough to hold fire.

#stemantics #geology #materialsscience #soapstone #finland

## Stats

- **Views:** 21,233
- **Likes:** 243
- **Shares:** 0
- **Comments:** 7

## Tags

finland, soapstone, materialsscience, geology, stemantics

---
Copyright (c) Gondola