Natural Rutilated Quartz - oval cabochon - black rutile quartz - 0.490 ct

Certificate : CA-QUAR026RB-003-094
Gem Type: Natural Clear Quartz
Weight: 0.490 Carat
Shape: oval
Size: 4.1 x 5.9 x 2.4 mm.
Color:  clear/black
Clarity: Transparent
Luster: submetallic
Treatment: heated to stabilise materials
Optical Phenomenon : rutilated ( black titanium dioxide inclusions trapped during the formation of quartz)

Birefringence : 0.285 to 0.296

• System: Tetragonal.
• Habit: Prismatic, acicular (needle-like), often elongated parallel to the c-axis.
• Symmetry: High symmetry (4/mmm)
• Key Features: High refractive index, large birefringence, high dispersion, giving it distinct colors and optical effects. 
• Formation: Rutile needles grow within or on quartz, often epitaxially, aligning with the quartz's crystal structure to minimize stress.
• Patterns: Can form random, parallel, star-shaped (sagenitic), or dense bundles.
• Color: Golden, red, silver, black (from rutile), with the quartz usually colorless.
• Significance: The interaction of their crystal structures (epitaxy) dictates the beautiful patterns, making it popular for jewelry

Crystallography : Hexagonal (tetragonal)
Dispersion : 0.28 (higher then diamond)
Luster : Vitreous
Hardness : 7
Refractive index : the host quartz, typically around 1.544–1.553, while the rutile inclusions themselves have a very high RI (2.616–2.903), 
Specific gravity : 2.651