Flint vs Obsidian
Flint and Obsidian are genuine alternatives to one another — a choice somebody actually makes — and differ on 2 measured properties, density most clearly.
Flint vs Obsidian
Flint
Silica so fine-grained it breaks like glass in a predictable direction — the material of the first tools, and of the first fires struck deliberately.
Obsidian
Volcanic glass, black and sharper than any steel — the other tool stone, and the one that can be dated and sourced precisely enough to map ancient trade.
| Property | Flint | Obsidian |
|---|---|---|
| Crystal system Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | amorphous |
| Density | 2.58–2.64 g/cm³ higher | 2.35–2.6 g/cm³ |
| Mohs hardness Mohs hardness is an ordinal scale: values can be ranked, but differences and ratios between them are not meaningful. | 7 higher | 5–5.5 |