Alabaster gypsum is a fine-grained, massive variety of gypsum (calcium sulfate dihydrate – CaSO₄·2H₂O) valued for its softness, uniform texture, translucency, and aesthetic appeal.
It must be clearly distinguished from calcite alabaster (CaCO₃), which is harder and acid-reactive. This product refers exclusively to gypsum alabaster, a sulfate-based decorative stone.
Alabaster gypsum is used primarily for sculpture, carving, decorative architecture, and luxury interior finishes, not for structural or metallurgical applications.
Chemical Composition
| Component | Typical Content |
|---|---|
| Calcium Sulfate Dihydrate (CaSO₄·2H₂O) | 95 – 99% |
| Water of Crystallization | ~20.9% |
| Silica (SiO₂) | <1% |
| Clay & Carbonates | Trace |
| Iron Oxides (coloring) | Trace |
Key Physical Properties
| Property | Typical Value |
|---|---|
| Crystal System | Monoclinic |
| Density | 2.2 – 2.4 g/cm³ |
| Color | White, cream, honey, pale yellow |
| Transparency | Translucent |
| Mohs Hardness | ~2 |
| Porosity | Low – Moderate |
| Water Solubility | Slightly soluble |
| Dehydration Temperature | ~100 – 150 °C |
⚠ Easily scratched with a fingernail
⚠ Sensitive to moisture and heat
Key Mechanical Properties
| Property | Typical Range |
|---|---|
| Compressive Strength | 15 – 30 MPa |
| Tensile Strength | 2 – 5 MPa |
| Flexural Strength | Low |
| Impact Resistance | Poor |
| Abrasion Resistance | Very Low |
| Elastic Modulus | ~5 – 10 GPa |
⚠ Not load-bearing
⚠ Requires controlled indoor conditions
Strengthening & Metallurgical Behavior
Strengthening behavior:
Alabaster has no intrinsic strengthening mechanisms.
Improvements are possible through:
• Resin impregnation
• Surface sealants
• Fiber-reinforced composite backing
Metallurgical behavior:
🚫 No metallurgical role. Alabaster decomposes before metallurgical temperatures
and converts to:
• Plaster of Paris (CaSO₄·½H₂O)
• Anhydrite (CaSO₄)
Key Characteristics
✔ Ultra-fine grain structure
✔ Homogeneous texture
✔ Excellent carvability
✔ Natural translucence
✔ Smooth polish
✔ Poor weather resistance
Refining & Processing Properties
Quarrying:
• Shallow open-pit or underground mining
• Hand extraction preferred
• Low blasting intensity
Processing:
• Block cutting
• Trimming and shaping
• Fine carving
• Polishing
• Optional sealing or resin treatment
Thermal processing:
• Gentle heating → Plaster of Paris
• Overheating causes strength loss
Available Forms
✔ Natural alabaster blocks
✔ Slabs and tiles
✔ Sculptural blanks
✔ Carved architectural elements
✔ Powdered alabaster
✔ Cast decorative panels
Applications
Decorative & Artistic:
• Sculptures and statues
• Carvings and relief panels
• Lampshades and light diffusers
• Ornamental bowls
Architectural Interiors:
• Columns and wall panels
• Decorative ceilings
• Domes and arches
• Luxury interior finishes
Industrial (Limited):
• Specialty plasters
• Fine casting molds
• Artistic casting material
Advantages of Alabaster Gypsum
✔ Exceptional aesthetic quality
✔ Easy to carve and shape
✔ Uniform texture
✔ Natural translucence
✔ High artistic value
✔ Low tool wear
Why Choose Alabaster Gypsum
Alabaster gypsum is the preferred material for intricate carving, decorative architecture, and luxury interiors. It offers superior workability, light diffusion, and artistic expression at a lower cost than marble, while remaining a time-tested decorative stone.
Alabaster Gypsum vs Marble
| Feature | Alabaster Gypsum | Marble |
|---|---|---|
| Hardness | Very Soft | Hard |
| Carvability | Excellent | Moderate |
| Translucency | High | Moderate |
| Structural Use | No | Yes |
| Moisture Resistance | Poor | Good |
| Cost | Lower | Higher |