Halite vs Sylvite
Halite and Sylvite are commonly confused, and 3 measured properties separate them — cleavage most clearly.
Halite vs Sylvite
Halite
NaCl
Rock salt — the only mineral people eat, and for much of history a commodity worth fighting over.
Sylvite
KCl
Potassium chloride, laid down where ancient seas dried out — the mineral that is potash, and the potassium in fertiliser.
| Property | Halite | Sylvite |
|---|---|---|
| Cleavage Categorical values can be listed side by side but not ordered or subtracted. | perfect cubic in three directions at right angles | perfect in three directions at right angles |
| Crystal system Categorical values can be listed side by side but not ordered or subtracted. | cubic | cubic |
| Density | 2.16–2.17 g/cm³ higher | 1.98–1.99 g/cm³ |
| Lustre Categorical values can be listed side by side but not ordered or subtracted. | vitreous | vitreous |
| Mohs hardness Mohs hardness is an ordinal scale: values can be ranked, but differences and ratios between them are not meaningful. | 2.5 higher | 2 |
| Streak Categorical values can be listed side by side but not ordered or subtracted. | white | white |
Why these get confused
cubic, colourless and found together; sylvite tastes bitter where halite is simply salty
The confusion is a real and documented one, not a resemblance we have invented.