Organic
Tree resin fossilised over 30 to 100 million years. Baltic amber runs butterscotch to cognac; Dominican material can be transparent blue under daylight; Burmese burmite is the oldest at roughly 99 million years and is the amber most often carrying insect inclusions.
Amber floats in saturated salt water, warms instantly in the hand, and smells faintly of pine when rubbed hard. Beware pressed amber (swirled 'sun spangles' throughout), copal (young resin, tacky under solvent) and plastic (heavy, no static charge).
Very soft and flammable. Keep away from perfume, alcohol and hot light. Clean with a damp cloth only.
Amber travelled the Amber Road from the Baltic to the Mediterranean before the Roman Empire, and Homer's Odyssey already names it among royal gifts.
Cultural history, recorded as tradition rather than as medical or scientific claim.
See it in person
Both rooms are open six days a week, and there is always someone happy to pull pieces out of the case so you can compare them under the light.