---
title: "Limestone — density, melting point and properties"
description: "Limestone has a density of 2,450 kg/m³ (2,000–2,700). Melting point, strength, conductivity, what it is used for, and whether it floats, rusts or is magnetic."
url: https://atoneplace.net/material/limestone/
site: "At One Place"
---

# Limestone

**Density of limestone: 2,450 kg/m³ (2,000–2,700)**

2.45 g/cm³ · 152.9 lb/ft³

By tonnage the most quarried rock on earth, mostly because cement is made by roasting it: heating calcium carbonate above 900 °C drives off carbon dioxide to leave quicklime, and that reaction is itself about half of the cement industry's emissions. As building stone it is soft, easily carved, and slowly dissolved by acid rain, which is why medieval limestone carvings lose their faces. The density band is wide because porosity varies enormously between a chalky and a compact limestone.

## Properties

- **Density:** 2,450 kg/m³ (2,000–2,700) — 2.45 g/cm³
- **Tensile strength:** 3–10 MPa
- **Young's modulus:** 40 GPa
- **Thermal conductivity:** 1.3 W/(m·K)
- **Hardness:** 3 Mohs
- **Thermal expansion:** 8 µm/(m·K)
- **Floats in water:** No
- **Magnetic:** No

## What it is used for

- Cement and lime manufacture
- Building stone and cladding
- Aggregate and road base
- Agricultural lime and flue gas desulfurization

## How it compares

*Water is 1,000 kg/m³. Anything with a shorter bar than water floats in it.*

- air: 1.2 kg/m³
- expanded polystyrene foam: 20 kg/m³
- rigid polyurethane foam: 40 kg/m³
- Water — the float line: 1,000 kg/m³
- limestone: 2,450 kg/m³
- tungsten: 19,250 kg/m³
- gold: 19,300 kg/m³
- platinum: 21,450 kg/m³

*Water is 1,000 kg/m³. Anything below that floats.*

| Material | Density | Relative to water |
| --- | --- | --- |
| rigid polyurethane foam | 40 kg/m³ | 0.04× |
| expanded polystyrene foam | 20 kg/m³ | 0.02× |
| air | 1.2 kg/m³ | 0.00× |
| limestone ← | 2,450 kg/m³ | 2.45× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |

## Does it rust?

Limestone contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.

## Is it magnetic?

Limestone is not a metal and has no ferromagnetic response.

## Common questions

### What is the density of limestone?

2,450 kg/m³ (2,000–2,700), or 2.45 g/cm³.

### Does limestone float?

No. At 2,450 kg/m³ it is denser than water.

### Is limestone magnetic?

Limestone is not a metal and has no ferromagnetic response.

## Related pages

- [Does limestone float?](https://atoneplace.net/does-it-float/limestone/)
- [Diamond](https://atoneplace.net/material/diamond/)
- [Granite](https://atoneplace.net/material/granite/)
- [Marble](https://atoneplace.net/material/marble/)
- [Quartz](https://atoneplace.net/material/quartz/)
- [Slate](https://atoneplace.net/material/slate/)
- [Sandstone](https://atoneplace.net/material/sandstone/)

## Sources

- United States Geological Survey — USGS (https://www.usgs.gov/) [Public domain (US Government)]