yeah, needs a strong heat source if it's a block. E.g. it's tricky to ignite a NeXTCube even with a blowtorch: https://simson.net/ref/1993/cubefire.html

"easily" is a relative term, it'll absolutely go up in a glorious blaze among any other actual fire but it won't set off at the slightest spark like fire starting powder or strips.

It's also a relatively pure sample, very soft, not an alloy like you'd see with magnesium casings. The block is actually a little deformed just from dropping it on the floor once.