Amber

Meaning: Amber (Indian: Kerwa; Italian: Ambra) is the hardened and fossilized resin of certain pine trees such as the Pinus succinifera.
Amber is either collected from sea shores or fished off the waters, or it is mined by open - pit mining. Yellowish-brown or honey color is the best known color for amber which are fished or mined along the coasts of Baltic Sea, these are popularly known as Baltic amber. Natural ambers are very old from hundreds to millions of years. Inclusions like frog, butterflies, lizards, spiders, ants, mosquitoes and other insect species inside amber decides its worth.
Copal resin (kauri gum) has similar appearance (simulant) that of an amber stone which is generally confused with real amber and mistakenly used in jewelry as amber beads.
Separation of real amber from plastic (imitation) amber.

	S.G.
Amber	1.08	floats
Salt Water	1.12	liquid
Plastic	1.20	sinks

Take a glass of water and add 2 spoon of salt in it. Now dip amber and plastic inside this saturated salt solution. According to Archimedes Principle, which states that, if the S.G. of the stone is greater than that of the liquid it will sink and if the S.G. of the stone is less than that of the liquid it will float. Therefore, amber starts to float on saturated salt solution while plastic sinks. This test is only for separation of amber from plastic and confirms that amber floats in saturated salt solution. Real amber having inclusions of insects may react differently to this test.

Properties

Chemical Composition: C₁₀H₁₆O + H₂S (approx.) as mixture of hydrocarbons, plus resins, succinic acid and oils

Types of Amber:

1. Sea Amber: found in the sea or washed up on the shore.
2. Pit Amber: dug up form pits.

Colors / Varieties: Yellow, brown, red (sourced from Myanmar), orange. Color depends on source and impurities. Transparency: Transparent to opaque. Transparency depends on gas bubbles.

Crystal System / Forms: None. Amorphous.

Hardness: 2 - 2.5

Specific Gravity: 1.05 - 1.09 (usually 1.08)

Cleavage / Fracture: None / Conchoidal.

Optic Character: Usually an aggregate (A.G.G.) or strong A.D.R. reaction. But, may show any reaction.

Lustre: Resinous or greasy.

Refractive Index / Birefringence: ±1.54 / Nil.

Pleochroism: None

Dispersion: None

Magnification: Amber is noted for its inclusions which are chiefly insects and leaves, gas bubbles, flow lines, other natural inclusions such as pyrite, calcite, etc.

U.V. Fluorescence: Bluish white in shortwave and yellow in longwave.

Spectrum: Not diagnostic.

Treatment (Enhancement): 

• Coating: darker colored materials are coated over the surface.
• Colorless and colored impregnation: to improve the clarity using rape seed oil. Color staining is done to get aged amber and also other colors.
• Heating: darkens the color in some varieties of amber, clarifies cloudy varieties with plenty of gas bubbles by heating in oil and causes stress cracks to form which is know as sun spangled amber.

Specific Tests & Remarks: 

• Amber floats in a saturated salt solution.
• Amber, pressed amber and copal resin break away in powdery splinters or chips with a knife and exhibit static electricity when rubbed.
• Amber, when burnt emits an aromatic odour.
• Amber does not soften with ether.
• Amber softens at about 150°C and melts at 250°C - 300°C.
• Amber often darkens with age to a fine red brown color.

Simulants (with key separation tests): 

• Pressed amber (amberoid): May show elongated gas bubbles and flow lines, outlines of varying clarity of each of the pieces pressed may be seen. Under longwave ultra violet lamp it may show blue white fluorescence. It is not affected by ether or acetone.
• Copal resin: A drop of ether or acetone will soften and form a stick path. Under shortwave ultra violet lamp it exhibits strong white fluorescence.
• Plastic (bakelite, celluloid, etc.): Higher S.G. than amber. Peels with a knife and floats in a saturated salt solution.
• Glass: R.I. & S.G.
• Chalcedony: S.G. Structure

Geological Occurrence: In sedimentary deposits and on shore lines.

Sources: 

• Along the coasts of the Baltic Sea, where 90% of gem quality amber is fished or mined.
• Other sources include Sicily, Romania, Dominican Republic, Mexico, Hawaii, Myanmar (red amber with higher S.G.), etc.

Cuts & Uses: Mostly as cabochons, beads, carvings, etc.