$25.00
Historic 1.5-inch Michigan fire brick fragment showing vitrified texture and kiln coloration — a tangible piece of industrial geology and regional history.
In stock
This 1.5-inch specimen of fire brick originates from Michigan’s historic industrial regions, where refractory materials once lined kilns and smelters. Each piece displays subtle orange, red, and buff tones with surface vitrification created by extreme heat. The tactile roughness contrasts with glossy, glass-like glaze patches — a result of long exposure to molten material.
Fire brick, also known as refractory brick, is a heat-resistant ceramic material composed primarily of alumina and silica. It withstands temperatures exceeding 1,500 °C and was essential in the copper and iron industries that shaped Michigan’s Upper Peninsula. The mineral composition and fine-grained texture enable structural stability under intense thermal cycling.
| Property | Value |
|---|---|
| Mineral Class | Silicate (Refractory Ceramic) |
| Chemical Formula | Predominantly Al₂O₃–SiO₂ |
| Crystal System | Polycrystalline Aggregate |
| Mohs Hardness | ~6–7 |
| Locality / Formation Type | Michigan industrial smelting region — refractory kiln lining |
Michigan’s industrial growth during the late 19th and early 20th centuries relied heavily on durable refractory materials. Fire brick fragments like this one are remnants of smelters and furnaces used in the Keweenaw Peninsula’s copper operations and regional foundries. They represent the fusion of geology and engineering — clay minerals transformed through human innovation into heat-defying stone.
The specimen’s warm earth tones, subtle glaze, and rough edges offer visual contrast between natural and engineered textures. Collectors appreciate fire brick for its textural authenticity, linking geological materials to industrial history and craftsmanship.
Symbolically, fire brick embodies endurance and transformation — representing materials that withstand heat and pressure while maintaining integrity.
Handle gently to preserve surface texture. Avoid soaking or harsh cleaning; a soft brush can remove dust without diminishing historical patina.
| Weight | 3 oz |
|---|---|
| Dimensions | 1.25 × .25 × 1.50 in |
