Some examples are: gold, silver, platinum, copper, mercury, etc.
no. platinum occurs naturally, but can me made in the laboratory
yes
Yes, even though it is a rare metal, it can be found in nature along with platinum, mercury, gold, and silver.
Yes. Platinum is a naturally occurring element, with atomic number 78.
Yes, you can trade it or evolve your own duskull. (Evolves at lvl 37) Not sure if they are found naturally though.
Jean Harlow
You can't find it naturally in HeartGold. It is a Pokemon found only in Sinnoh. But you can trade if from Pokemon Diamond, Pearl, or Platinum if you do want one.
Platinum is an element.
Platinum is usually found pure.
Ozone is found naturally in stratosphere. It is found as ozone layer.
Hydrangea are plants, and are naturally found in the ground.