Comparison · Minerals vs Organic Gems
Calcite vs Red Coral
Calcite and Red Coral are easy to confuse. Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Calcite and Red Coral
- Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Calcite is transparent, Red Coral is opaque.
- They overlap in orange and pink, but Calcite also comes in clear, yellow, blue, and green and Red Coral also comes in red and white.
Calcite vs Red Coral properties
| Property | Calcite | Red Coral |
|---|---|---|
| Type | Minerals | Organic Gems |
| Mohs hardness | 3 | 3.5 |
| Luster | vitreous | vitreous |
| Streak | White | White |
| Transparency | transparent | opaque |
| Specific gravity | 2.7 | 2.65 |
| Crystal system | trigonal | trigonal |
| Common colors | Colorless, White, Yellow, Orange, Blue, Green, Pink | Red, Pink, Orange, White |
| Rarity | common | rare |
| Typical specimen value | $2–$100+ | $50–$3000+ |
Which is more valuable?
Red Coral is usually the more valuable of the two: a typical collector specimen runs about $300 against $15 for Calcite, and premium Red Coral can reach $3000 or more.
About Calcite
Calcite is one of the most common minerals on Earth, found in sedimentary, metamorphic, and igneous rocks. It's the primary component of limestone and marble.
About Red Coral
Precious coral is formed from the skeletons of marine animals. Red coral from the Mediterranean has been prized for jewelry for thousands of years.
Calcite vs Red Coral FAQ
Is Calcite the same as Red Coral?
No. Calcite is a mineral while Red Coral is a organic gem. Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Calcite from Red Coral?
Both sit near Mohs 3, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Calcite is transparent, Red Coral is opaque. They overlap in orange and pink, but Calcite also comes in clear, yellow, blue, and green and Red Coral also comes in red and white.
Which is harder, Calcite or Red Coral?
Red Coral is harder: Mohs 3.5 against Mohs 3 for Calcite.
Which is more valuable, Calcite or Red Coral?
Red Coral is usually the more valuable of the two: a typical collector specimen runs about $300 against $15 for Calcite, and premium Red Coral can reach $3000 or more.
