| Features | Index |
| Category | Granite |
| Hardness | 6-7 |
| Heat Resistance | High |
| Acid Resistance | Medium (sensitive to strong acids) |
| Maintenance | Moderate (waterproofing required) |
| Common Uses | Bancadas, ilhas, painéis decorativos, pisos internos, fachadas internas. |
| Reference standard 15.845/2015 |
Python Black Processing Techniques
The Python Black is a metamorphic gneisscharacterized by its black color with wavy white and gray veins,that resemble the pattern of a snake’s skin, which inspired its commercial name.
Average Mineral Composition
- •Quartz: 25–35%
- •Alkali Feldspar + Plagioclase: 40–50%
- •Biotite and dark micas: 15–20%
- •Accessory minerals (garnet, iron oxides, ilmenite, pyroxene): up to 5%
Properties
- Hardness: 6–7 Mohs (good scratch resistance)
- •Water absorption 0.4%–0.6% (higher than granite, requires sealing)
- Compressive strength: 150–180 MPa (lower than pure granites)
- Chemical resistance: y show sensitivity to strong acids (vinegar, lemon), which can cause localized dullness
The Python Black is considered an exotic material of high aesthetic value, widely used in refined and sophisticated design projects.
INFORMATION FOR FABRICATORS (Stone Workers)
Recommended Finishes
- •Polished: enhances contrast between the black background and light or golden veins.
- •Brushed (Leather): satin matte finish, modern and elegant.
- •Honed: uniform matte finish, ideal for indoor floors and wall panels.
- Flamed: not recommended due to fragility in micaceous zones.
Processing and Cutting
- This stone machineswell but contains micaceous zones (rich in biotite) that can exfoliate, so extra care is needed when cutting.
- High-performance diamond blades for metamorphic materials are recommended (350 mm OS–31SS or Diapar DP-1015).
- Reinforcing with epoxy resin is advisable in areas with higher vein concentration.
Sealing
Due to its moderate porosity and the presence of oxidation-prone minerals, sealing is mandatory..
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.
- •Also protect sides and edges of countertops and floors.
- • Reapply every 1–2 years in high-use areas.
Adhesive Bonding
- Use epoxy or polyester adhesives (Tenax Fix Top, Bellinzoni Blitz Mastic, Argacon Marmofix).
- Pigment the adhesive in black or gold, according to the veins.
INSTALLATION
- Countertops: support every 60 cm; fix using white or black PU40 adhesive.
- Indoor floors: use ACIII white or gray adhesive mortar.
- Avoid installing in high-traffic outdoor areas, as gneiss is more susceptible to wear.
CLEANING AND MAINTENANCE
- Routine: damp cloth and neutral detergent.
- Avoid: vinegar, lemon, chlorine, or strong acidic cleaners.
- Post-construction: use appropriate cleaners such as Quartzolit Post-Construction, PCS Alkaline – Piso Clean, or Bellinzoni Floor Cleaner.
FINAL CONSIDERATIONS
The Python Black Gneiss is a striking stone with boldvisual movement featuring white and light veins over a deep black base.Although it offers good physical resistance,it requires more maintenance than graniteespecially regarding sealing and protection against acids. It is ideal for kitchen islands, decorative panels, powder rooms, and other refined interior applications, adding exclusivity and value to design projects.
