| Characteristics | Value |
| Hardness | 6-7 |
| Heat Resistance | High |
| Acid Resistance | Medium (sensitive to strong acids) |
| Maintenance | Moderate (waterproofing required) |
| Common Uses | Countertops, interior floors, decorative panels, stairs, interior facades. |
| Reference standard 15.845/2015 |
Waterfall Beneficiation Techniques
The Waterfall is a metamorphic gneiss, with a unique aesthetic with a light to grayish background marked by long vertical veins in shades of white, beige, gray and sometimes rusty, reminiscent of the visual effect of a waterfall (hence the commercial name). It is considered a exotic material, widely used in architectural projects with high aesthetic impact.
Average Mineral Composition
- Quartz: 30–40%
- Feldspars (Plagioclase + Alkaline Feldspar): 40–50%
- Biotite and dark micas: 10–15%
- Accessory minerals (iron oxides, garnet, tourmaline): up to 5%
Properties
- Hardness: 6–7 Mohs → moderate scratch resistant.
- •Water absorption 0.4% – 0.6% → moderate, requires waterproofing.
- Compressive strength: 150–180 MPa (smaller than quartzites/granites).
- Chemical resistance: reasonable, may lose shine in contact with strong acids (lemon, vinegar).
Due to its linear appearance, Waterfall is widely used in vertical panels and internal facades, where the cascade effect can be better appreciated.
INFORMATION FOR FABRICATORS (Stone Workers)
Recommended Finishes
- •Polished: highlights the light veins and adds depth to the waterfall effect.
- •Brushed (Leather): sophisticated satin matte finish on countertops and panels.
- •Honed: uniform matte, suitable for indoor floors.
- Flamed: not recommended (fragility in micaceous areas).
Processing and Cutting
- Waterfall has typical foliation planes of gneisses, which require attention when cutting to avoid chipping.
- Use high-performance diamond discs for metamorphic materials.
- Sheets with significant grain movement may require epoxy resin prior to polishing.
Sealing
Due to moderate porosity and the presence of micaceous minerals, mandatory waterproofing is recommended.
Recommended Products:
- •Brazil: Rock Protect – Chemistone, Nano Effect – AKEMI, Idea Gold – Bellinzoni
- •International: Proseal – Tenax, Stain Proof – Dry Treat, Idea Gold – Bellinzoni
Procedure:
- Apply water repellent with a brush/roller to all surfaces and sides.
- Reapply every 1–2 years indoors and annually outdoors.
Adhesive Bonding
- Use epoxy/polyester glues suitable for ornamental rocks (Tenax, Bellinzoni, Argacon).
- Pigment in light, gray or beige tones, depending on the predominant color of the plate.
INSTALLATION
- Countertops: support every 60 cm, gluing with white PU40.
- Indoor floors: laying with white ACIII mortar.
- Facades: preferably in systems of ventilated facade with mechanical fixing, for greater security.
CLEANING AND MAINTENANCE
- Routine: damp cloth and neutral detergent.
- Avoid: vinegar, lemon, chlorine, bleach and abrasive products.
- Post-construction: Quartzolit Post-Construction, PCS Alkaline – Clean Floor, Bellinzoni floor cleaning detergent.
FINAL CONSIDERATIONS
The Gnaisse Waterfall is a material of strong aesthetic appeal, whose appearance evokes the movement of waterfalls. It offers exclusivity and sophistication em projetos de high standard, being ideal for countertops, stairs, interior panels and decorative facades. Requires preventive maintenance and adequate waterproofing, but provides unique visual results that are valued in the market.
