That's a good question as amber isn't a true mineral - it's a mixture of different elements which is why it's properties vary.

Amber is an organic substance - originally a form of tree resin whose structure has changed very little over time.

The general properties of amber are as follows:

• Moh's scale of hardness: between 2 and 2.5
• Refraction index of 1.54
• Melting point between 150 and 180
• Colours - all varieties of cognac and golden yellow from opaque to transparent, ivory, brown, green, black, very rarely blue and cherry.
• Chemical make-up 80% carbon, 10% hydrogen, 10% oxygen. Small quantities of sulphur.
• A clean, resinous fragrance
• Presence of plant and animal inclusions

Interestingly amber contains a varying percentage of amber acid. Baltic amber is unusual in that its acid content is between 3% and 8%. All other amber worldwide contains less than this or none at all.

It is worth noting that Mineralogists refer to Amber as succinite which is based on the Latin name for amber - succinum