There is no difference between arduin and blue stone: they are two names for exactly the same Belgian stone. “Arduin” is the Flemish technical term, “Belgian blue stone” is the commercial name, and “Petit Granit” is the official designation. So, whether you order an arduin threshold or a blue hardstone threshold, you’ll receive the same stone. Below, we explain where the names come from and what you should keep in mind when placing an order.
| Name | Who uses it? | Context |
|---|---|---|
| Arduin | Flemish craftsmen and older generations | Colloquial and technical language: “a bluestone threshold” |
| Belgian blue stone | Retail and Online Stores | The common trade name |
| Petit Granit | Official documents and certificates | The official name—despite the name, it is not granite |
The name dates back to a time when stonemasons thought the sparkling crinoids (fossilized sea lilies) on the surface resembled the crystals in granite. Geologically, however, the stone is limestone, formed on the floor of a tropical sea, not volcanic rock. You can read more about its origin in Where does Belgian blue stone come from?.
The real distinction isn’t between bluestone and blue hardstone, but between Belgian stone and Asian imitations sold as “blue stone.” Vietnamese and Chinese blue stone are geologically different and generally more porous, which is a factor to consider in our freeze-thaw climate. Therefore, always ask about the origin and the certificate; at Renier, the stone comes from Belgian quarries. Be sure to also read our Comparison: Belgian vs. Imported.
What is the difference between arduin and blue stone? None: These are two names for the same Belgian stone. “Arduin” is the Flemish technical term, “Belgian blue stone” is the commercial name, and “Petit Granit” is the official designation.
Is Petit Granit a type of granite? No. Despite its name, it is a limestone. The name refers to the sparkling crinoids on its surface, which resemble granite crystals.
Is every “blue stone” bluestone? No. Asian blue stone is also sold as blue stone, but it is geologically different and generally more porous. Ask about its origin and certificate.