Understanding Portland Whitbed Testing: Why Jordans, Grove and Fancy Beach Whitbed Share the Same Technical Data
Portland Stone has been used on some of Britain's most prestigious buildings for centuries, valued not only for its appearance but also for its consistency, durability and proven performance.
One question occasionally raised by architects and specifiers is why Portland Jordans Whitbed, Portland Grove Whitbed and Portland Fancy Beach Whitbed all share the same Technical Data Sheet, CE certification and Declaration of Performance (DoP).
The answer lies in the geology of Portland Whitbed itself.
One Geological Bed, Three Aesthetic Variations
Within Jordans Mine, Portland Stone is extracted from three principal beds:
- Portland Roach
- Portland Whitbed
- Portland Basebed
Portland Basebed forms a clean and uniform section of stone, typically around 3 metres thick within the mine. Above this sits Portland Whitbed, which generally ranges between 3 and 4 metres in thick.
Unlike Portland Basebed, the Whitbed contains greater natural variation in shell content and appearance. This is largely because the Whitbed was formed later in the geological sequence, at a time when the shallow tropical seas covering Portland were richer in marine life. As a result, a greater abundance of shells and marine organisms became incorporated into the stone, creating the distinctive fossil content that characterises Portland Whitbed today.
These natural variations are divided into three commercial products:
Importantly, these classifications are based entirely on appearance.
The differences relate to the quantity and distribution of visible shell content, allowing architects and designers to select the aesthetic that best suits their project. They do not represent different geological stones or different performance grades.
One Stone, Different Appearance
From a geological perspective, Jordans Whitbed, Grove Whitbed and Fancy Beach Whitbed are all part of the same Whitbed formation.
The stone has the same mineral composition, the same geological origin and the same fundamental characteristics. The only difference is the amount and distribution of visible shell content present within the stone.
A cleaner section of Whitbed may be classified as Jordans Whitbed, while areas containing a greater concentration of shells and fossils may be marketed as Grove Whitbed or Fancy Beach Whitbed. These distinctions help designers achieve their desired aesthetic but do not indicate any meaningful difference in the stone itself.
In fact, even under microscopic examination, it would not be possible to distinguish between these three Whitbed variations based on their geological composition.
Proven Through Testing
When Albion Stone first began extraction from Jordans Mine, we investigated whether the visual variations within the Whitbed had any effect on technical performance.
Samples were taken from different areas of the same extraction face. This included cleaner material that would now typically be classified as Jordans Whitbed, along with shellier material that would be classified as Grove Whitbed and Fancy Beach Whitbed.
The results showed no significant difference in performance between the various aesthetic grades.
Any minor variation observed fell within the normal range expected when testing natural stone and was no greater than the variation typically associated with laboratory testing itself.
The findings confirmed what the geology had already suggested: these products may look different, but they perform as the same stone.
Why the Technical Data is Combined
Because Jordans Whitbed, Grove Whitbed and Fancy Beach Whitbed all originate from the same geological bed within the same mine, Jordans Mine, and demonstrate the same engineering performance, Albion Stone tests and certifies them as a single material group.
All three products are simply aesthetic variations of Portland Whitbed. They are extracted from the same Whitbed horizon, formed under the same geological conditions and share the same mineralogical characteristics. As a result, there is no technical justification for treating them as separate stones when assessing performance.
This means that the results presented within our Technical Data Sheets, CE Certificates and Declarations of Performance (DoP) are drawn from testing carried out across Portland Whitbed production from Jordans Mine.
This approach provides a more representative dataset and ensures that the published technical information is fully applicable to any Portland Whitbed extracted from Jordans Mine, regardless of its aesthetic classification. As the stones come from the same geological bed and have been shown through testing to exhibit the same performance characteristics, architects and specifiers can be confident that the test data is valid across the entire Portland Whitbed range.
Confidence for Architects and Specifiers
For architects, conservation professionals and contractors, the key message is simple.
Choosing between Portland Jordans Whitbed, Portland Grove Whitbed and Portland Fancy Beach Whitbed is an aesthetic decision, not a performance decision.
Whether a project calls for the cleaner appearance of Jordans Whitbed or the richer fossil character of Grove Whitbed or Fancy Beach Whitbed, the stone originates from the same geological bed, from the same Portland Stone Mine and exhibits the same proven performance characteristics.
As a fourth generation family business, Albion Stone takes pride in its knowledgeable and dedicated workforce. By combining traditional craftsmanship with modern manufacturing techniques, we produce Portland Stone of the highest quality while minimising our environmental impact.
