Colored paraffin wax and waterThe lava in a lava lamp is made out of oil, water, and carbon tetrachloride, commonly used in fire extinguishers.
No there is NOT real lava in lava lamps. If there was real lava in lava lamps, it would burn, it just oil and water.
Slow lava is more viscous.
Oil and wax.
Not sure, but that's like asking why was Earth named Earth, JUST 'CAUSE.