Question about jade or amber..

Is it possible to get jade or amber in any other way besides faction transfers?

Rare Material trader has it sometimes. Sells for 1300 gp last time I saw. But people buy them as fast as possible to resell at 3K+.

I had a jade drop for me from a monster.

Yep, rare monster drops. I got an amber from one of the mantises running around in Kurzik territory.

I got Jadeite from salvaging a normal, white jade wand. I also had 3 pieces fall from normal monsters in Rhea's Crater area on Luxon side while fighting Outlaw Luxon bad guys. Probably would have gotten more but I use full team of henchs and they get some of those drops.

With the need for the rarer crafting materials like steel and silk and such I pick up EVERYTHING and salvage it. I get lots of steel and silk doing this. I also get a lot of wood, which I don't need, and glittering dust.

I had a Jadeite drop for me outside of the Marketplace.
Other than that, try to buy from people, I saw them yesterday in Cavalon and people were selling for 2k and 1.5k each which is great compairing to 7k the week before.