amorphous Simulant amber simulant

Ambroid (Pressed Amber)

Formula Compressed and fused amber chips (same chemical composition as amber — fossil resin; succinite for Baltic amber)

Crystal Structure

CDL Notation

 #! Species: Ambroid (reconstituted/pressed amber)
#! System: Amorphous (fossil resin)
#! Habit: Massive; streaky colour zones from compression
amorphous[resinous]:{massive}

Crystal System amorphous

Point Group none

Crystal Forms (1)

{massive}

Quick Facts

Hardness

2.0

Specific Gravity

1.05

Refractive Index

1.53

Optical Character

Isotropic

Physical Properties

Crystal System: amorphous
Hardness (Mohs): 2.0
Specific Gravity: 1.05
Cleavage: None
Fracture: Conchoidal
Lustre: Resinous

Optical Properties

Refractive Index: 1.53
Birefringence: 0
Optical Character: Isotropic
Fluorescence: Blue-white (LWUV; similar to amber)

Origin & Identification

Origin: Simulant
First Produced: 1880
Diagnostic Features: Elongated flattened bubbles (vs spherical in natural amber — most diagnostic under microscope); streaky colour zones at chip boundaries; angular junction planes between compressed fragments; FTIR: same as amber (not distinguishable by FTIR alone); float/acetone tests same as amber

Characteristics

Colours

YellowOrange-yellowOrange; may show streaky swirling colour distribution from compression

Common Inclusions

Elongated bubbles (from pressing process; diagnostic); streaky flow-lines; angular fragments of original amber chips visible under magnification at junction zones

Notes

Ambroid is a simulant produced by compressing/fusing small amber chips and fragments under heat and pressure (autoclave compression); also called "reconstituted amber" or "pressed amber." Same chemistry as amber; FTIR spectrum matches amber (Baltic succinite shoulder ~1150 cm-1 present). Main diagnostic: elongated/flattened bubbles from pressing process (natural amber has round spherical bubbles); streaky colour zones at chip boundaries visible under microscope; angular junction planes between compressed fragments. Float test identical to amber (SG 1.05-1.09). RI identical to amber (1.530-1.545). Acetone test: ambroid resists acetone (like amber; fully polymerised) — distinguishes from copal. Gemmological knowledge from Read 7th ed. (DOI 10.4324/9780080507224) [PARTIALLY_SUPPORTED]. Introduced commercially c.1880s when amber scrap from cutting was compressed to make larger pieces. Note: ambroid is NOT an imitation of a different material — it IS amber (same composition) but reconstituted; the "simulant" classification reflects its commercial deception as "natural unmodified amber." Target: natural amber.