Sometimes the obvious is not what it appears. Take amber, a substance used in necklaces and other jewelry. It looks like a rock or a mineral. But every piece of amber actually started out inside a tree.

The obvious may also not be what it appears when you buy jewelry or a decorative item made from “amber.”


Amber comes from trees

Amber is organic, meaning it derives from a living organism — a plant or an animal. In amber’s case a tree.

The substance originated millions of years ago as tree sap or resin. When a tree suffered a wound, resin might drop to the ground. If the soil was a muddy ooze, the resin would slowly sink.

Over time minerals would replace the sap’s original tissue molecule by molecule. Although the original cell structure remains, it’s now composed entirely of minerals. The substance has become petrified — amber.


Amber preserves the past

Amber has unique preservation abilities. Sometimes, before the resin sank below the surface, its sweetness would attract an insect. As the creature fed, the resin’s stickiness might trap it. Occasionally, a leaf would fall and stick to the soft resin. More resin may fall, completely encasing whatever has stuck to it.

Amber has been found that has trapped and perfectly preserved entire insects, spiders, small lizards, even frogs.

The preservation of plants and animals appearing as they actually lived millions of years ago has been invaluable to scientists and archaeologists, revealing much about ancient flora and fauna.

Scientists identified a 100 million-year-old ant entombed in amber as a worker ant, thus they concluded it was part of a social hierarchy. Until then, they had believed that social hierarchy among ants developed much later.

Amber’s preservation abilities have also been valuable to author Michael Crichton who wrote Jurrasic Park. In his book, Chrichton’s characters clone dinosaurs using DNA — the basic genetic building block — extracted from amber-preserved mosquitoes that had fed on dinosaur blood.

In 1993 scientists came close to duplicating the fictional feat of the researchers in Jurrasic Park when they extracted DNA from an amber-preserved, dinosaur-era weevil. Their success with this 124 million-year-old extinct insect leads researchers to believe that most animal remains preserved in amber have DNA they can extract and study.


Where it’s found

Europe has been a source of much amber, especially the Czech and Slovak republics, the Netherlands, Poland, Romania, Scandinavia and Sicily. One of the greatest concentrations was found along the Baltic Sea’s southeastern shore. Between 1885 and 1914 miners dug up a million pounds of amber around what is today Kaliningrad, Lithuania.

The current hot spot, though, is the Dominican Republic, source of Jurrasic Park’s amber. Much amber is embedded in the sandstone of the country’s northern highlands.


Amber the gem

Amber was one of the earliest substances used for decoration. It appears as irregular masses, nodules or drops. Gem-quality amber ranges from transparent to translucent. Its color from yellow to brown. A rare piece may be colored blue by its mineral content.

Prices vary widely. Least valuable is semi-opaque brown amber. Yellow amber brings a higher price. And if it has an interesting pattern or an entombed insect, it’s even more valuable.


Buyer beware

If your travels give you an amber-buying opportunity, you need to be cautious. Imitations are sold as the real thing.

The most notorious fake is plastic. Kauri gum, a less-valuable resin from New Zealand’s Kauri pine trees, may also be passed off as amber. Still another fake comes in the form of ambroid, a pressed amber. It’s made by heating and fusing small pieces of amber.

Tests will reveal whether a piece of amber is authentic:

• Amber’s 1.05-1.09 specific gravity (its weight compared to an equal volume of water), is lower than plastic’s. So plastic will sink in concentrated salt water. Amber will not.

• Amber is relatively soft and you can sometimes scratch it with your fingernail, but always with a copper coin or glass.

• You can identify ambroid fairly easily by looking for the parallel bands and elongated bubbles which form during its pressing.

A once-favored trick to identify amber was to rub it on your clothing. Amber generates static electricity that will pick up bits of paper. Unfortunately, Kauri resin and plastic do too.

While you might be able to perform some tests before buying raw amber, they are impractical for amber jewelry. So you need to buy from a reputable, well-established store. If you’re making a substantial purchase, consider having an independent jeweler appraise the piece.