GIF 1: An angle grinder being used on a metal rod, a huge torrent of sparks flying off.
GIF 2: Someone standing at a slight distance using an angle grinder on a piece of metal, a streak of sparks flying off to the side.
GIF 3: A rod being pushed into a belt grinder, a stream of sparks flying downwards.
GIF 4: Slow motion footage of a log collapsing in a fire during the nighttime, a small explosion of sparks flying up.
GIF 5 (center): A heart-shaped sparkler and a star-shaped sparkler held next to each other, both lit and sparkling.
GIF 6: Slow motion footage of sparks flying in front of the camera due to something off screen, blue smoke drifting through the air.
GIF 7: A medium-light skinned person using an angle-grinder to cut a screw and hex nut off a rusted piece of machinery, sparks flying off to the right.
GIF 8: An angle grinder being used on a very large chain link, sparse sparks flying off.
GIF 9: An angle grinder being used on a circular piece of metal with many sparks flying downwards.
Think of the lava spawner as an opaque, non-animated, solid, overpowered lava source block. When placed, the lava spawner would generate lava source blocks around itself and would regenerate if the lava sources were removed. It could be broken instantly regardless of the tool used to break it. It did not emit light nor damage entities, and sponges were able to soak it up. It was removed in Java Edition Infdev 20100624.