First, Boba is a mandalorian. He was raised as one, even if Jango was killed when he was only 10 years old, many cultures consider boys at around that age to be full men, thus, a Mando.
Also, lightsabers "virtually" cut through anything. Some material are to dense for a saber to cut through, and you need enough strength to cut through them. I.E. remember in the beginning of ep1 when Qui-Gon didn't just continue cutting a circle, or start a new one, when the Trade Feds closed the blaster doors?
Cortosis, for instance, is so dense that it can short out a lightsaber if held in a position or in a slow cut, because the dense material/molecules would restrict/stop/reflect (take your pick) the blade's energy particles. Although the same is true for Mandalorian Iron, it's effect at blocking a lightsaber or shorting it out is less then that of Cortosis.
Different materials, density, and molecular make up can effect a saber in different ways. So take your pick.
Oh, and electo-plasma swords are supposed to be lightsaber "resistant". A Dathomar Witch was able to withstand Maul's sabers for a while I believe, and was to have preceeded the lightsabers for the sith: (go "histories" then "M" and go to the bottom of the page(sorry it won't let me directly link))
I know most of your already know this, I'm just throwing it out there cuz I'm bored, and I used too have WAY to much time on my hands.