A useful way to understand the two properties is to consider the balance between softness and strength. Pyrophyllite’s layers slide readily under pressure, allowing the material to deform and transmit pressure. However, the material must also resist being squeezed out at the boundary between the anvils and the pressure chamber. If it flows too easily, the sealing edge may lose its shape and supporting force. Conversely, if the material is too hard to deform, it may not conform to gaps effectively. The material therefore needs a suitable balance of deformability, strength, and elastic recovery. This explanation is an interpretation of the reported structure–property relationship, not a quantitative model presented in the uploaded paper.

Elastic recovery during decompression also matters. A later study found that pressure-transmitting efficiency and sealing performance do not necessarily rise or fall together. For example, Pyrophyllite 4 transmitted pressure efficiently at high pressure but was prone to sealing failure during decompression after high-pressure treatment. Pyrophyllite 2 had somewhat lower pressure-transmitting efficiency at high pressure, yet retained better elastic recovery and sealing performance. Thus, a material should be evaluated not only by how much loading force is needed to reach a given pressure, but also by whether it can decompress safely and reliably.

Common approaches to adjusting performance include:

Controlling mineral composition. The uploaded paper reports that, in its samples, the combined content of layered impurities could be up to 10% without affecting pressure transmission and sealing, while non-layered impurities such as feldspar and quartz should be kept low; above 5%, they impaired flow and deformation. Small amounts of iron- and titanium-bearing minerals may improve sealing. These findings should be verified for the specific ore and equipment rather than treated as universal formulation limits.

Grinding, blending, and pressing. A review notes that using natural pyrophyllite blocks directly can lead to variation in product performance. Grinding the ore and pressing it into the required shape can reduce the effects of uneven mineral distribution.

Controlling heat treatment. The review links pyrophyllite’s water content to its deformation behaviour. It reports that prolonged heating above 500°C can drive off bound water, so heating conditions need to be controlled. The optimum temperature may differ by source and should not be assumed to be the same for all pyrophyllite.

Using composite media. Pyrophyllite–dolomite composite structures are commonly used to combine material properties and adjust thermal, pressure-transmitting, and sealing conditions. Their performance depends on the specific design and operating conditions; one component should not be assumed to simply replace the other.

The review also describes pyrophyllite as serving several roles, including pressure transmission, sealing, insulation, and support. Because these requirements affect the stability of the synthesis chamber together, the material should be assessed across the full compression and decompression cycle—not by a single measurement alone.