You don't use a stone at all. Eevee evolves into Umbreon via happiness, followed by a level up AT NIGHT.
so far, you cannot evolve eevee either to umbreon or espeon on FireRed because on FireRed and LeafGreen, there is no clock system. You must trade eevee to Emerald for evolving to Espeon or Umbreon
You can't. It evolves by the time of day. Since there isn't a clock, eevee won't evolve into espeon OR umbreon.
No; Umbreon didn't exist that early in the series.
To get an Umbreon, you have to trade your Eevee to Pokemon Ruby, Sapphire, or Emerald, because there needs to be time if you're going to evolve Eevee into Umbreon. Keep Eevee with you until its happiness is at its highest, then evolve it with a moonstone WHEN IT IS NIGHT ACCORDING TO THE GAME CLOCK.
you cant umbreon doesn't exist in fire red
To make Eevee evolve into an Umbreon, you have to level it up with high happiness at night.
you can't. to get an espeon or umbreon, you need to evolve an eevee at certain time of day. leafgreen/firered don't have clocks. you have to trade the eevee to ruby/sapphire, max out friendship and level up in the pm for espeon, am for umbreon.
Eevee doesn't have a set level to evolve into Umbreon. All you have to do to evolve it is max out its happiness at night. ~KKMG1
Evolve it at 12 pm
Eevee evolves to Umbreon when it has high happiness, and it levels up while it is dark.
You have to wait a while after you get to pick who evee will evolve into (umbreon) You have to wait a while after you get to pick who evee will evolve into (umbreon)
you can't, you have to max out eevee's happiness at night to evolve it into Umbreon.