The sport of Auto Racing.
No. When opals were first found in Australia, they were not thought to be opals because they were a milky white in appearance. Opals found elsewhere in the world were mostly black.
Opals are amorphous because they have no definitve shape. As an example, quartz has a specific crystal shape. Opals can be any shape.
Soccer
Nobody MADE opals. They're mined out of the ground.
It represents rugby.
Tennis
swinning
Opals cannot be used as foods. They are hard, precious stones.
Neither opals or any other gemstone will make you invisible.
Some opals are known as black opals, this is when they have a mainly black colour. In general a black opal is very dark blue and has flecks of other colours within
Speed Sheep Shearing