Description
Discover the subtle charm of this Natural Dark Opal Type 1, a genuine gemstone from Lightning Ridge, known for its unique features:
- Variety: Natural Dark Opal Type 1
- Body Tone: Black N5 (9)
- Brightness: Average
- Transparency: Transparent
- Colour: Blue with pale tones
- Shape: Oval Outline
- Profile: Low Cabochon
- Pattern: Blocky Pattern
- Display: Weak or blank from two angles
- Colour Distribution: 40–49% coverage
- Inclusions: None
Physical Properties:
- Absorption Spectra: 660nm, 470nm
- Birefringence: None
- Category: Mineraloid (Amorphous)
- Cleavage: None
- Crystal Form: Amorphous, pseudomorph, botryoidal
- Crystal Habit: Irregular ‘nodular’ veins
- Composition: Hydrous silicon dioxide (3–21% water content)
- Density: 2.09
- Transparency: Transparent to opaque
- Fluorescence: May phosphoresce under long/short wave UV
- Fracture: Conchoidal – Uneven
- Group: Silicates; Tectosilicates; Silica Group
- Lustre: Vitreous to Resinous
- MOHS Scale: 4.5 – 6.5
- Polish: 2.15 ± 0.08-0.09
- Refractive Index (R.I.): 1.450 ± 0.020
- Specific Gravity: 1.98 – 2.25
- Streak: White
- Solubility: Methanol, Humic, Hydrofluoric Acid
Valuation:
- Carat Weight: 7.35 Carats
- Price Per Carat: $19.12
- Total Value: $140.53
This opal’s pale blue tones, blocky pattern, and transparent clarity offer an understated beauty, making it an affordable choice for collectors and those seeking a natural gemstone with subtle elegance.
Note: This valuation was conducted for insurance purposes and is intended for private and confidential use only. Reproduction or unauthorized use is prohibited.
