Description
Uncover the brilliance of this Natural Black Opal Type 1, a remarkable gemstone from Lightning Ridge, showcasing the following features:
- Variety: Natural Black Opal Type 1
- Body Tone: Black N1 (3)
- Brightness: Bright
- Transparency: Translucent
- Colour: Blue/Green with normal tones
- Shape: Oval Outline
- Profile: Low Cabochon
- Pattern: Mixed Pattern
- Display: Weak or blank from one angle
- Colour Distribution: Over 80% coverage
- Inclusions: Visible only under a loupe
Physical Properties:
- 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
- Carat Weight: 3.95 Carats
- Formula: SiO₂nH₂O
- Fracture: Conchoidal – Uneven
- Lustre: Vitreous to Resinous
- Fluorescence: May phosphoresce under long/short wave UV
- Absorption Spectra: 660nm, 470nm
Additional Information:
- Category: Mineraloid (Amorphous)
- Crystal Habit: Irregular ‘nodular’ veins
- Composition: Hydrous silicon dioxide (3-21% water content)
- Crystal Form: Amorphous, pseudomorph, botryoidal
Valuation:
- Price Per Carat: $350
- Total Value: $1422
This opal features bright blue-green hues, a black N1 body tone, and a translucent clarity that makes it a standout choice for collectors and jewelry enthusiasts. Its mixed pattern and exceptional brilliance ensure timeless elegance and appeal.
Note: This assessment is for insurance purposes and is intended for private and confidential use only.
