/ the magic of colors, crystal enamels interplay with volcanic surfaces
Lava stone is a visionary stone: unconventional and multifaceted. It can be transformed from the grays of magma patterning into a striking spectrum of different glazes.
Glazes serve to color, decorate and waterproof the stone surface.
A ceramic glaze is an impervious layer of a vitreous substance which has been fused to the stone body through firing. Kiln firing increases the resistance of glazed stone surfaces – a key factor in indoor and outdoor furnishings. Glazing makes stone surfaces highly resistant and almost indestructible when exposed to water, chemicals, temperature fluctuations or UV light.
A closeup view of a lava stone tile demonstrates the benefits of glaze on lava as a protective coating for any kind of decor.
The enamel layer: the stone is covered by a crystalline varnish and then fired. The enamel creates an impervious coating which is fused to the stone body. Through this type of glazing, the lava stone surface becomes unaffected by UV rays, is frost-resistant, waterproof and almost completely indestructible. For lava tiles which are to be used in places such as staircases and poolsides, nonslip glazes can be applied.
The engobe: is the layer underneath the enamel, a clay that blocks any small holes or imperfections within the stone.
The stone: the volcanic stone is ideal for any outdoor features, e.g. swimming-pool coatings, thanks to its heat accumulation capacity.
How we glaze
The glazing of lava stone requires scrupulous workmanship and every stage is done by hand.
Many factors are taken into account, including the features of the lava stone piece, which, since it is natural, are not always uniform.
After being cleaned, completely dried and covered with a clay paste called engobe, which serves to close any microscopic holes or imperfections in the stone, we come to the main stage, i.e. applying the previously prepared and mixed liquid clay glaze.
Being sprayed onto the stone the liquid clay creates different characteristics depending on the effect desired.
This step is repeated several times, bringing into play the skill of the craftsman.
Once glazed, the lava stone piece is left to dry naturally.
The last stage before firing is the application of a vitreous glaze over the colored surface.
The transparent glaze is prepared by mixing several raw materials as well as various minerals and oxides to obtain the desired color, level of gloss and finish.
The last step is firing, which takes place in computer-controlled kilns. The firing cycle varies and can last for 13 to 14 hours at temperatures exceeding 1000° C. Cooling is a slow process, which often takes up to 24 hours; in order to avoid thermal shock and ensure the piece does not break.
During firing, the minerals in the stone may rise to the surface and react with the glaze, creating holes or stains or slightly changing its color. Sometimes, however, small fractures inside the stone can be stressed and may appear through the glaze.
Of course, all these results depend on the stone’s mineral composition, and they will vary from one piece to the next, so are impossible to predict.
However, it is this unpredictability that makes the natural stone and the glazing process beautiful and unique.
At Ranieri we live by the strong conviction that we are committed to building a sustainable society by delivering products that last a lifetime (and even longer). Respecting the environment comes naturally at Ranieri, since the environment is our most precious resource.
We transform lava stone into sustainable products that evoke emotion with long-lasting quality and value.
One of lava stone’s most important characteristics is its ability to endure. The material is completely recyclable so there’s no additional burden on natural resources.