Beauty, features and natural imperfections of the volcanic surfaces

What is faulty product when we go for natural organic stones and handcrafted finishing?
The understanding of the gray and enameled lava stone features is a crucial step, through which our partners and our customers will fulfill their expectations as regards quality and beauty.

The lava stone may be subject to variations in shade and occasional “aesthetic imperfections” that are just peculiar characteristic of both natural stone and handcrafted finishing.
Lava stone is a raw stone that contains many minerals, and during the process of firing different chemical reactions are possible, and could leave aesthetic traces on the surface.
Buying a lava stone product, you should be aware that the product may, on occasions, include: pinhole cavities, darker spots, green spots, mineral spots, for which there is a tolerance parameter as shown in the photos.
Another peculiarity of the lava product is the possible slight variation in the size, in the range of +/- 1.5 mm, due to the dilatation during the firing.
The enameling process itself may cause a variation in the thickness of the piece, in the range of +/- 0.5 mm.
It is also possible that the pieces bend slightly (2/4mm approximately).
Hereafter we share a few examples of “aesthetic imperfections” which may occurs both in bare and enameled lava surfaces.

Natural imperfections on bare lava surfaces

Mineral spot (approx. 5 mm)
Variations in shade on bare lava surfaces

Natural imperfections on glazed lava surfaces

Darker spot (approx. 1 mm)
Pinhole cavities (approx 1mm)
Darker outlines near the edges
crystal craquelé on colored enamel (crazing, which can have different dimensions)
Craquelé on white enamels (crazing, which can have different dimensions)

Shade variations

Another feature which may occur on lava stone surfaces is the variations in shade.
All the natural products vary in shade and in the structure of the piece.
The pieces undergo an exhaustive sorting process at Ranieri Lava Stone and any that do not meet our quality standards are rejected, nevertheless, variation in shade may affect both the gray lava surface, as part of the natural stone, and the glazed lava surface, as part of the glazing process.
As a matter of fact, the variation in shade is an inherent part of the glazing process, where it may occur due to the accumulation of enamel along the piece end edges, and more generally as a result of the craft enameling.
The shade variation can be an added value of crystalline colors, while matte enamels are not affected by this feature.
Shade variation is unpredictable; its occurrence makes each piece unique and unrepeatable.
The feature is part of the beauty of the lava product.

The shade variation can be an added value of crystalline colors:

The same color will react differently form flat to 3D pieces, as you can note comparing the following applications:


Samples here are indicative just to show what the surface could look like when glazed. They are not control samples.
If you need a control sample, please make sure to ask for one at the moment of order.
We will make it for you without any shipping cost.
We invite you to visit our extensive gamma of bare lava surfaces, solid colors, and patterns, where you can easily ask for control samples and better understand the product features.

Discover more about our surfaces and ask for your samples here: