Blue amber
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Blue amber is amber exhibiting a rare coloration. It most commonly is found in the Dominican Republic and highly valued by collectors.
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[edit] Color
[edit] Causes of coloration
It is not fully understood what causes the blue coloration. One theory links the rare properties to the occurrence of volcanic ash or dust which was present when the resin was first pressed out from Hymenaea protera millions of years ago. Another suggests that due to volcanic activity hot lava must have flown over those areas where regular amber was buried under ground. Due to the extreme heat, the amber changed its color first to green and then to blue. Experiments have shown that a change of color occurs when normal amber is heated up. It has also been postulated that enclosures of pyrites may give a bluish color to amber. But we do know that it is a result of fluorescence and not solid color. Ultra-violet or violet light is re-emitted as blue or green, an effect attributed to the presence of poly-nuclear aromatic molecules.
[edit] Appearance
Under artificial light, the amber appears like ordinary amber, but under sunlight it has an intense fluorecent blue glow. When held against the sun it will appear like ordinary amber, and under ultraviolet light it will glow a bright milky-blue. This effect can be compared to the ocean, which, although transparent, can appear anything from light blue to dark blue to black, depending on depth, mass, salinity, etc.
Blue amber emits a very agreeable smell (aromatic molecules), which is different from regular amber when it is being cut and polished.
