Some can be magnetic but the answer is
Yes, iron is magnetic.
NOT all metals are magnetic
the area of magnetic force around a magnet is called the magnetic field
No. Magnetite and, to a lesser degree, hematite are magnetic.
No; opals have no magnetic properties.
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.
Nobody MADE opals. They're mined out of the ground.
Yes. Some forms of green rhyolite are known for their magnetic characteristics.
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
Three different types of Opal are found in Australia:Fire Opals are mined in South Australia near Coober Pedy.Black Opals are mined in New South Wales near Lightning Ridge.Boulder Opals are mined in the western Queensland.
No they do not shrink.
Yes. Coober Pedy is still a major producer of opals.