| Characteristics | Value |
| Hardness | 6-7 |
| Heat Resistance | Very High |
| Acid Resistance | Good |
| Maintenance | Low (waterproofing recommended) |
| Common Uses | Countertops, floors, facades and exteriors |
| Reference standard 15.845/2015 |
Processing techniques for Black São Gabriel Granite
The Granito Preto São Gabriel is a fine to medium grained gabbro/norite, by heart homogeneous black, without marked veins, valued for its aesthetic uniformity.
Average Mineral Composition
- Plagioclase (Labradorite/Anorthite): 40–50%
- Pyroxene (augite) and mafic minerals: 30–40%
- Biotite and iron oxides: 5–10%
- Quartz: <5%
Properties
- Hardness: 6–7 Mohs (good scratch resistance)
- •Water absorption 0.1% – 0.2% (very low, excellent performance in kitchens).
- Compressive strength: > 220 MPa.
- Chemical resistance: withstands household products well, low tendency to oxidation.
It is one of the most stable and sought-after black granites on the international market, comparable to Black Absolute (Zimbábue).
INFORMATION FOR FABRICATORS (Stone Workers)
Recommended Finishes
- •Polished: most common finish, highlights the intense black.
- Brushed/Leather: creates a satin surface, reduces reflection, a trend in modern kitchens.
- •Honed: uniform matte, good for floors.
- Flamed: non-slip finish, suitable for facades and outdoor areas.
Processing and Cutting
- This stone high density and low porosity, easy to cut and polish.
- It is recommended to use diamond discs for high hardness granite (e.g.: Disc 350 mm OS–31SS, Diapar DP-1015).
- Allows for framing, straight cuts, drilling and gluing with an excellent finish.
Sealing
Even though it is not very porous, it is recommended to waterproof countertops to prevent the absorption of oils/greases.
Recommended Products:
- •Brazil: Rock Protect – Chemistone, Nano Effect – AKEMI, Idea Gold – Bellinzoni
- •International: Proseal – Tenax, Stain Proof – Dry Treat, Idea Gold – Bellinzoni
Procedure:
- Apply to a clean, dry surface with a brush or roller.
- In the case of floors, also apply to the edges and sides.
- Reapply every 2–3 years in high-use areas.
Adhesive Bonding
- Use high-adhesion epoxy/polyester glues (Tenax Fix Top, Bellinzoni Blitz Mastique, Argacon Marmofix).
- Use black pigment to even out the joints.
INSTALLATION
- Countertops: support every 60 cm, fixed with white/black PU40 glue. Avoid industrial silicones (they can stain).
- Indoor/Outdoor Floors: laying with white or gray ACIII mortar. Flexible grout. Waterproof after the mortar has cured.
CLEANING AND MAINTENANCE
- Daily cleaning: water + neutral detergent.
- Avoid: abrasive products or strong acids (chlorine, aggressive degreasers).
- Post-construction: use specific cleaners (Quartzolit Pós-Obra, Bellinzoni floor cleaning detergent, PCS Alcalino – Piso Clean).
FINAL CONSIDERATIONS
The Granito Preto São Gabriel is considered one of the most resistant and stable rocks on the market, with low porosity, high durability and sophisticated aesthetics.
For your homogeneidade e resistência, is widely used in kitchens, high-traffic floors, ventilated facades and outdoor areas.
