The product commercially sold as Amber resin today comes from India. It is a soft sugary compound or masala of various aromatic components - attars, oils, tree resins, gums and powders. Used traditionally, a small piece placed in a rosewood or sandalwood box can release fragrance for a very long time. It is sometimes burned on top of charcoal. Because there is no ingredients list when it comes to commercially available amber, we can't be sure that it is a purely natural product, though some claim to be organic. Nonetheless. amber is an enchanting scent. So what makes it smell like that?  

Common ingredients found it Indian Amber that contribute to it's distinctive scent:

• liquid benzoin resin
• liquid styrax resin
• Galbanum resin
• rockrose
• sandalwood
• flower attars such as jasmine or champa
• herbs such as patchouli
• binders such as beeswax or ghee

Some excellent varieties of Amber can be purchased on these sites: 
http://tenzingmomo.com/
http://www.somaluna.com/amber-incense-resins/

Indian Amber does not usually work well as an incense ingredient for cones, sticks, or dhoop because it contains wax (usually beeswax) or ghee- clarified butter.  Most commercially available Incense that is labeled "Amber" fragrance is scented with a synthetic fragrance oil and is not a natural product.  But solid amber has natural origins. 

True Fossilized Amber Resin. This is tree sap that has been buried in the earth for long amounts of time, and is fossilized.  It is said to have a fragrance when ground up and burned but from my sources, it is not a remarkable fragrance.  it is available from online dealers for this purpose.  

Historically, true fossilized resin has a long history of use in magic, ritual, and the crafting of ritual objects. It is associated with the Sun.

We love this story from the Somaluna.com website:

 "The Greek name for this amber was elektron, "formed by the sun", and it was connected to the sun god Helios, one of whose titles was Elector or the Awakener. According to the myth, when Helios' son Phaëton was killed, his mourning sisters became poplars, and their tears became the origin of elektron, amber. The ancients also noted that if they rubbed the amber for long enough, they could even get an electric spark to jump.  Our word electricity comes from their word for Amber."