Singular- field plural- fans and players
I don't see any outstanding flaws with the grammar. So I would say it is correctly written.
Lava is seen to have a "glittering"effect due to its natural composition: literally minerals. Depending on the rock that has been melted into this mixture, lava or magma can have varying effects applied to it's appearance, density, and the temperature it cools at.
They are sources that you can find the date, author, and have real facts and not just made up. Like if you went to the IRS website then that is a credible source for tax where as going to Wiki they are not credible because anybody can go there