Got a photo? Identify rocks instantly with the Rockby app
Open the appDescription
Amber is an amorphous organic substance, a fossilized resin from ancient trees. It is not a mineral in the strict sense because it lacks a crystalline structure and a definite chemical composition. However, it is widely recognized and treated as a gemstone. Its color varies widely, from pale yellow to deep brown, often with orange or reddish tints. It can be transparent, translucent, or opaque. A distinguishing feature is its low density, allowing it to float in saltwater. Amber often contains inclusions of ancient insects, plants, or air bubbles, which significantly increase its scientific and aesthetic value.
How to Identify
- Color
- Ranges from pale yellow to deep orange, brown, red, and rarely green or blue. Often cloudy or opaque due to microscopic air bubbles.
- Luster
- Resinous to waxy.
- Texture
- Smooth, warm to the touch. Can be brittle.
- Crystal Form
- Amorphous; no crystal structure.
- Cleavage
- None, exhibits conchoidal fracture.
- Geological Environment
- Typically found in sedimentary deposits, particularly in marine glauconitic sands, lignite seams, or alluvial deposits. Often associated with ancient forest environments that were subsequently submerged or buried.
Key Facts
- Hardness: 2.0-2.5 on the Mohs scale (very soft)
- Specific Gravity: 1.05-1.10 (floats in saltwater)
- Crystal System: Amorphous (no crystal structure)
- Color: Yellow, orange, brown, red, green, blue
- Luster: Resinous, waxy
- Transparency: Transparent to opaque
- Fracture: Conchoidal
- Cleavage: None
- Composition: Complex mixture of organic compounds, primarily polymerized isoprenoids (C10H16O) with varying amounts of succinic acid (especially in Baltic amber).
Quick Check
- Color: Yellow, orange, brown, red (rarely green, blue)
- Luster: Resinous to waxy
- Streak: White (not typically performed due to softness)
Physical Characteristics
- Crystal Habit: Irregular masses, nodules, stalactitic forms, or rounded pebbles (when water-worn).
- Cleavage Type: None
- Fracture Type: Conchoidal, brittle
- Tenacity: Brittle
- Luster Type: Resinous to waxy
Formation
Amber is fossilized tree resin, not sap. Resin is produced by certain trees as a protective mechanism against insect infestation and fungal infection. Over millions of years, this resin undergoes a process of polymerization and hardening, losing its volatile components and becoming stable. This process, known as resinitization, occurs under specific geological conditions, typically involving burial in sedimentary environments (e.g., marine sediments, lignite seams) where it is protected from oxidation and microbial degradation. Pressure and temperature over geological timescales contribute to its transformation into amber.
Usage
Primarily used as a gemstone for jewelry, ornamental objects, and carvings. Historically, it has been used in folk medicine, perfumes, and as an incense. Its scientific value is immense, as inclusions (insects, plants, small vertebrates) preserved within amber provide invaluable insights into ancient ecosystems and evolutionary biology.
Age Distribution
Typically Cenozoic Era, ranging from Eocene (approx. 40-50 million years ago) to Miocene (approx. 5-23 million years ago), though some amber can be much older (e.g., Cretaceous amber).
Where to Find
Baltic Sea Region
The most famous and prolific source, particularly along the coasts of Poland, Russia (Kaliningrad Oblast), Lithuania, Latvia, Estonia, Germany, Denmark, and Sweden. Baltic amber (Succinite) is primarily Eocene in age.
Dominican Republic
Known for its clear amber, often with spectacular insect inclusions. Miocene in age, and distinct from Baltic amber in its botanical origin.
Mexico (Chiapas)
Produces amber similar to Dominican amber, also Miocene in age, with notable insect and plant inclusions.
Myanmar (Burma)
Burmite, primarily Cretaceous in age, is scientifically significant for its ancient inclusions, including dinosaurs and early birds. Often reddish-brown.
Canada (Alberta, Manitoba)
Cretaceous amber, often found in association with coal seams, providing insights into ancient North American ecosystems.
Finding Tips
Saltwater Test
Amber has a low specific gravity (1.05-1.10) and will float in a saturated saltwater solution (approximately 2-3 tablespoons of salt per cup of water), whereas most imitations (glass, plastic) and copal will sink.
Hot Needle Test
Carefully heat a needle and touch it to an inconspicuous spot on the specimen. Genuine amber will emit a faint, pleasant pine-like odor and the needle will leave a small, brittle mark. Plastic will smell like burning plastic, and glass will not be affected. Use caution to avoid damage.
UV Light Test
Many types of amber, especially Baltic amber, will fluoresce a pale blue or greenish-yellow under shortwave or longwave UV light. Copal may show a weaker or different reaction, and plastics typically do not fluoresce in the same way.
Rubbing Test
Rub the specimen vigorously on a soft cloth. Genuine amber will become electrostatically charged and attract small pieces of paper or dust. It will also emit a faint, resinous aroma when warmed by friction.
Observe Inclusions
Natural inclusions in amber (insects, plant fragments) often appear lifelike and three-dimensional, sometimes with signs of struggle. Bubbles, if present, are typically irregular. In fakes, inclusions may look too perfect, or bubbles may be perfectly round.
Similar Rocks
Copal
Immature Resin
Also known as: Young Amber
Glass
Silicon Dioxide (amorphous)
Also known as: Man-made Glass
Plastic
Various Polymers
Also known as: Resin Imitation
Scientific Classification
- Mineral Class
- Organic Gemstone (not a true mineral)
- Group
- Fossilized Resin
- Crystal System
- Amorphous
- Chemical Formula
- Variable, generally (C10H16O)n, with Baltic amber (Succinite) containing 3-8% succinic acid.
- Composition
- Polymerized hydrocarbons, primarily isoprenoids, with oxygen, hydrogen, and carbon. Trace elements and organic acids (like succinic acid) vary by origin.
Explore Amber
Identify rocks anywhere
Free on iOS, Android, and Web. Photo identification, full database, and your personal collection.