Comparison · Minerals
Aragonite vs Borax
Aragonite and Borax are easy to confuse because both are minerals. Aragonite is harder (Mohs 3.5–4) than Borax (Mohs 2–2.5), so Aragonite will scratch Borax and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Aragonite and Borax
- Aragonite is harder (Mohs 3.5–4) than Borax (Mohs 2–2.5), so Aragonite will scratch Borax and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
- Aragonite feels noticeably heavier for its size (specific gravity 2.93–2.95 versus 1.7 for Borax).
- They overlap in clear and gray, but Aragonite also comes in yellow, blue, and pink.
- Well-formed crystals give it away: Aragonite is Orthorhombic, Borax is Monoclinic.
Aragonite vs Borax properties
| Property | Aragonite | Borax |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 3.5–4 | 2–2.5 |
| Luster | Vitreous to resinous | Vitreous to resinous, earthy when dehydrated |
| Streak | White | White |
| Transparency | Transparent to translucent | Transparent to translucent |
| Specific gravity | 2.93–2.95 | 1.7 |
| Crystal system | Orthorhombic | Monoclinic |
| Common colors | Colorless, White, Yellow, Gray, Blue, Pink | White, Colorless, Gray |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$150+ |
Which is more valuable?
Typical specimens of Aragonite and Borax trade in a similar range, around $20.
About Aragonite
Aragonite is calcium carbonate, CaCO3, crystallizing in the orthorhombic system as a metastable polymorph of the more common mineral calcite. It readily forms in low-temperature settings such as caves, hot springs, and the shells of many marine organisms, and it slowly converts to calcite over geologic time. Twinned crystal clusters resembling six-rayed stars are among its most recognizable forms.
About Borax
Borax is a hydrated sodium borate mineral, Na2B4O7·10H2O, that crystallizes from the evaporation of alkaline lakes in arid basins. It has been mined and used by humans for thousands of years as a cleaning agent, flux, and preservative, making it one of the more historically significant evaporite minerals. Borax dissolves readily in water and gives off a sweetish alkaline taste, reflecting its high solubility compared to most rock-forming minerals.
Aragonite vs Borax FAQ
Is Aragonite the same as Borax?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Aragonite is harder (Mohs 3.5–4) than Borax (Mohs 2–2.5), so Aragonite will scratch Borax and not the other way round. A fingernail (Mohs 2.5) scratches it easily.
How can you tell Aragonite from Borax?
Aragonite is harder (Mohs 3.5–4) than Borax (Mohs 2–2.5), so Aragonite will scratch Borax and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Aragonite feels noticeably heavier for its size (specific gravity 2.93–2.95 versus 1.7 for Borax). They overlap in clear and gray, but Aragonite also comes in yellow, blue, and pink.
Which is harder, Aragonite or Borax?
Aragonite is harder: Mohs 3.5–4 against Mohs 2–2.5 for Borax.
Which is more valuable, Aragonite or Borax?
Typical specimens of Aragonite and Borax trade in a similar range, around $20.
