Preto Siena Granite

Preto Siena Granite is a deep dark gray to near-black background enriched with fine to medium crystalline mineral grains that create a subtly textured and slightly variegated appearance quarried in Brazil. Its visual character is generally uniform and elegant, with occasional lighter gray and silver-toned mineral flecks that add depth and a soft shimmering effect, especially noticeable in polished finishes. The stone presents a balanced and sophisticated look, neither highly veined nor heavily patterned, making it suitable for contemporary and minimalist design applications. Its texture is medium-grained and densely crystalline, composed of tightly interlocking quartz, feldspar, and mica minerals, resulting in a compact structure with high hardness, excellent mechanical strength, and low water absorption.

Physical and Mechanical Properties

• Water Absorption: < 0.45% (very low, contributing to its resistance to staining and making it ideal for kitchen and bathroom applications)
• Density: Approximately 2,630 - 2,640 kg/m³ (indicative of its compact structure)
• Flexural Strength: Around 13 - 15 MPa (good for countertop applications and structural uses)
• Compressive Strength: Approximately 210 - 230 MPa (high strength, suitable for heavy-duty flooring and outdoor paving)
• Hardness: Rated between 6 and 7 on the Mohs scale (very hard and durable)
• Porosity: Low, typically less than 1% (contributes to its durability and ease of maintenance)
• Slip Resistance: Generally classified as R9 – R10, depending on the finish (moderately slip-resistant, so caution is advised in wet areas)

Chemical and Mineral Composition (Percentage by Weight)

• Quartz: 25% - 30% (provides hardness and resistance to weathering)
• Feldspar: 40% - 45% (contributes to the coloration and uniformity)
• Mica (Biotite and/or Muscovite): 5% - 10% (adds sheen and subtle sparkle)
• Other Minerals: 5% (trace minerals can include amphiboles, pyroxenes, etc.)

Usage

• Interior Applications: Countertops, flooring, wall cladding, bathroom vanities, fireplace surrounds
• Exterior Applications: Facades, outdoor paving, monuments
• Commercial Uses: Office building lobbies, hotel interiors, and retail spaces

Maintenance

• Regular Cleaning: Use a soft cloth and pH-neutral cleaner to maintain shine and prevent streaks.
• Sealing: It is advisable to seal the granite annually to protect against stains and enhance its appearance.
• Avoid Harsh Chemicals: Do not use acidic or abrasive cleaners which can dull the surface.

Cutting Sizes (Common)

• Slabs: Typical sizes include 2 cm and 3 cm thickness
• Tiles: Commonly available in sizes like 30 x 30 cm, 60 x 30 cm, 60 x 60 cm
• Custom Sizes: Can be cut to specifications for unique architectural features

Surface Finish Options

• Polished: High gloss finish that enhances the color and mineral detail, making it popular for countertops and indoor wall cladding.
• Honed: Provides a smooth, matte finish that is less prone to appearing scratched or worn.
• Leathered: Offers a textured, tactile surface with a unique appearance, often used for countertops.
• Flamed: A rough surface that is slip-resistant, ideal for outdoor paving and stairs.
• Brushed: A finish that provides a worn-in look with subtle texture and depth enhancements.

Preto Siena Granite thus combines elegance with practicality, making it an ideal choice for a wide range of design applications. Its physical and mechanical properties ensure longevity and resilience, while its mineral composition provides a distinctive aesthetic.