What is a mineral used in making fertilizer?

  today was great day in my life. i got to watch a lok sabha election closely for the first time in my life. it was an awesome experience for me as i have never seen this before. i have been so enthusiastic to see this from a very long time. i am not of 18 years or above of age so i didn't get a chance to vote. but i got selected as a social service volunteer in the polling booth. i was there giving water to people who needed it, physically disabled people etc,. i then got the chance to see the polling closely while taking some of the people who weren't able to go and vote by themselves. i was very much amazed by seeing the voting pattern and how the voters get painted on their finger in order to prevent cheating. voting is the most important process of our country to elect a respective people's representative. i will never forget this experience as i learned a lot of new things about voting and elections today.