| Characteristics | Value |
| Category | Granite |
| 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 |
Bahamas Beneficiation Techniques
The Bahamas is a metamorphic gneiss, characterized by a predominantly light (white to beige) with veins and movements in grayish, golden and brown tones, which recall the aesthetics of tropical beaches, hence its commercial name. It is a material exotic, highly valued in sophisticated projects.
Average Mineral Composition
- Quartz: 30–40%
- •Alkali Feldspar + Plagioclase: 40–50%
- Biotite, micas, and dark minerals: 10–15%
- Accessory minerals (iron oxides, garnet, tourmaline): up to 5%
Properties
- Hardness: 6–7 Mohs → scratch resistant.
- •Water absorption 0.4% – 0.6% → moderate, requires waterproofing.
- Compressive strength: 150–180 MPa (lower than pure granites)
- Chemical resistance: stable against household agents, but may lose shine in contact with strong acids.
It is considered a material noble and decorative, ideal for high-end indoor applications.
INFORMATION FOR FABRICATORS (Stone Workers)
Recommended Finishes
- •Polished: highlights the light background and contrasting veins.
- •Brushed (Leather): satin matte finish, very elegant on countertops and panels.
- •Honed: uniform and discreet finish, ideal for indoor floors.
- Flamed: not recommended (fragility in micaceous areas).
Processing and Cutting
- Relatively stable rock, but with micaceous zones (micas and biotite) that can exfoliate.
- Recommended use of high performance diamond discs for quartzite/gneiss.
- On sheets with significant grain movement, reinforcement with epoxy resin may be necessary before polishing.
Sealing
Due to moderate porosity and the presence of minerals susceptible to oxidation, 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 on a clean and dry surface using a brush or roller.
- Waterproof edges and cuts before installation.
- Reapply every 1–2 years in high-use areas.
Adhesive Bonding
- Use epoxy/polyester glues specifically for ornamental rocks (Tenax, Bellinzoni, Argacon).
- Pigment in light or brown tones to harmonize with the material.
INSTALLATION
- Countertops: support every 60 cm, gluing with white PU40.
- Indoor floors: white ACIII adhesive mortar.
- Not recommended for high-traffic outdoor floors due to the presence of micaceous minerals.
CLEANING AND MAINTENANCE
- Routine: damp cloth and neutral detergent.
- Avoid: vinegar, lemon, chlorine and abrasive products.
- Post-construction: Quartzolit Post-Construction, PCS Alkaline – Clean Floor, Bellinzoni floor cleaning detergent.
FINAL CONSIDERATIONS
The Gnaisse Bahamas is a material of aesthetic and sophisticated impact, valued for its light background and moving golden and grayish veins. It is widely used in high-end interior design projects, as countertops, islands, panels and stairs, and can be applied to interior facades. Requires more careful maintenance than granite, mainly in relation to waterproofing and protection against acids, but it offers incomparable exclusivity and beauty.
