Gravina Tufa is a large-grained, porous volcanic tuff (tufa) stone quarried in Puglia, Italy. Known for its distinctive golden yellow-beige color and unique texture, this stone is formed from compacted volcanic ash and is highly valued for its aesthetic and functional properties. Below is a detailed description of its characteristics, applications, and specifications:

Texture and Pattern

Texture: Large-grained and highly porous, with a rough, natural texture.

Pattern: Irregular pores and voids, along with subtle variations in color, give it a rustic and organic appearance.

Technical Specifications

Density: Approximately 1.4–1.6 g/cm³, making it lightweight compared to other natural stones.

Water Absorption: Typically 20–30% by weight, due to its porous nature.

Compressive Strength: Around 10–15 MPa, suitable for non-load-bearing applications.

Flexural Strength: Approximately 2–4 MPa, indicating limited structural use but excellent for decorative purposes.

Chemical and Mineral Composition (% by weight)

Silica (SiO?): ~50–60%

Alumina (Al?O?): ~10–15%

Calcium Oxide (CaO): ~5–10%

Iron Oxide (Fe?O?): ~3–5%

Potassium Oxide (K?O): ~2–4%

Magnesium Oxide (MgO): ~1–3%

Other Minerals: Trace amounts of volcanic glass, feldspar, and clay minerals, contributing to its porous structure and color.

Applications

Gravina Tufa is primarily used for decorative and architectural purposes due to its lightweight and porous nature. Common applications include:

Wall Cladding: Adds a rustic, natural aesthetic to interior and exterior walls.

Landscaping: Ideal for garden features, retaining walls, and decorative boulders.

Sculptures: Easy to carve and shape, making it a popular choice for artistic creations.

Facades: Used for ventilated facades due to its insulating properties.

Decorative Elements: Fireplace surrounds, fountains, and accent pieces.

Maintenance

Cleaning: Use a soft brush or cloth with mild soap and water. Avoid high-pressure washing, which can damage the porous surface.

Sealing: Highly recommended to apply a penetrating sealer to reduce water absorption and prevent staining.

Avoid: Harsh chemicals or acidic cleaners, which can erode the stone.

Cutting Sizes (cm)

Blocks and Boulders: Standard sizes include 100x50x30 cm or larger, depending on the quarry.

Tiles: Common sizes include 30x30 cm, 30x60 cm, and 40x40 cm, with thicknesses of 2–4 cm.

Custom Cuts: Available for specific project requirements.

Surface Finish Options

Natural: Rough, untreated surface that highlights the stone’s porous texture.

Brushed: Slightly smoothed surface with a rustic finish.

Sandblasted: Textured, non-slip surface ideal for outdoor use.

Honed: Smooth, matte finish for a more refined look.

Conclusion

Gravina Tufa is a unique and versatile volcanic stone that combines aesthetic appeal with functional properties. Its golden yellow-beige color, porous texture, and lightweight nature make it a popular choice for decorative and architectural applications. Whether used for wall cladding, landscaping, or artistic projects, this stone adds a touch of natural elegance and rustic charm to any space.