Coral (Proteinaceous) | Gemopedia

Coral has been prized throughout history for its natural beauty. Like pearl, coral is also an organic gem consisting of more than 90% calcium carbonate. All coral consists of the remains of skeleton-like support structures that were built by colonies of very small marine animals, known as coral polyps.
Alternate
Names
Black Coral, Golden Coral, King's Coral, Akori Coral
Colors
Black, Dark Brown, Golden, Yellow, Blue

Coral (Proteinaceous) Classification

Common Name

Coral (Proteinaceous)

Species

NA

Variety

Colors

Black, Dark Brown, Golden, Yellow, Blue

Alternate Names

Black Coral, Golden Coral, King's Coral, Akori Coral

Gemstone Groups

Key Separations

RI, appearance and magnification

Comments

Black to dark brown=King's coralYellow to brownish yellow=golden coral sometimes bleached black coral. light to medium dark blue=Akori coral

Coral (Proteinaceous) Optical Properties

Transparency

Semitranslucent - Opaque

Refractive Index

1.56-1.57
Tolerance:(+0.010/-0.010)

Birefringence

Optic Character

Optic Sign

Polariscope Reaction

Aggregate (AGG)

Fluorescence

SWUV: inert
LWUV: inert

CCF Reaction

Pleochroism

None

Dispersion

Comments

Coral (Proteinaceous) Chemistry & Crystallography

Chemical Name

Chemical Formula

C32H48N2O11

Synthesis

Crystal System

NA

Classification

Organic

Nature

Natural

Crystallinity

Non-Crystalline

Comments

Coral (Proteinaceous) Characteristic Physical Properties

Hardness

3

Streak

Specific Gravity

1.3-2.12 Typical:1.35

Toughness

Good

Inclusions

In cross section conchiolin coral has a tree ring like growth structure with concentric and circular rings. Sometimes the rings will look like white crescents. The surface of the branch will have a bumpy appearance. Black coral is sometimes bleached to look like golden coral and will visually appear to have a rougher texture.

Luster

Vitreous

Stability

Fracture

Conchoidal, Uneven

Cleavage

None

Comments

JTV on Google+
0 Items
My Wish List
Close
Item
Description
Qty.
Price


Estimated Order Total:
0
Total Due Today:
0
Close
Item
Description
Qty.
Price


Page of 1