Now that you have finished the Cianwood City gym, you might need to get the medicine for the Ampharos. Unless you already got it, if you don’t then just go pick it up. Now head to the lighthouse in Olivine City. In the lighthouse you’ll have to slowly work your way to the top again. Give the Ampharos the medicine, Jasmine should be grateful now, and head back to the gym.
The Olivine City gym is a steel type gym. Steel Pokemon are usually quite defensive and it will be tough to get them down unless you have some Pokemon with advantages, a fire type could work. Jasmine is the name of the gym leader. Jasmine has a title of The Steel-Clad Defense Girl, and is the first steel type gym leader ever. She is apparently has trouble speaking because she is very shy. Anyway, when the battle begins Jasmine will send out a Magnemite. Don’t let it paralyze your Pokemon because it could get very annoying, I suggest you bring a Paralyze Heal just in case. The first Magnemite should go down pretty easy, so go ahead and fight it for a while and it should faint. After the first Magnemite is defeated, a second Magnemite will be sent out. This Magnemite is absolutely no different from the first. It is an exact copy, just defeat it in the same way and be cautious in case it uses Thunder Wave or if some random electric type attack paralyzes it. It should go down and be defeated pretty easily.
Now that’s over so your finished with the Magnemite. Now Jasmine will send out her last and most powerful Pokemon, Steelix. The Steelix is at level thirty five, it will be tough to defeat it, Steelix has high defense. It will also be holding a Sitrus Berry, which will restore some of it’s health. That only makes it harder to knock down. If you have a water type you can probably take out the Steelix quickly. This is because Steelix is also a ground type Pokemon so water will have an advantage over it. If you can take out the Steelix you will win the gym battle. If you win you will receive the sixth gym badge, the Mineral Badge.