[quote=@rechonq]
[@Rex]
Quick question, what are the types of dust, and can they be combined for different effects?
[/quote]

Wind or Air - A "primary" type of Dust, known to correspond to green crystals.
Fire - Fire is mentioned by Weiss Schnee in "The Shining Beacon" as a type of Dust. Miles states that red crystals are Fire Dust in the RWBY Volume 3 Live Stream. In "Ruby Rose", a henchman calls the red crystals "Burn Uncut" (also seen in closed caption subtitles) which might be a name for the Fire Dust type.
Water - Mentioned by Weiss in "The Shining Beacon"
Lightning - Mentioned by Weiss in "The Shining Beacon"
Ice - A "secondary" type of Dust, formed by the combination of Water and Air Dust.
Steam - A "secondary" type of Dust, formed by the combination of Water and Fire Dust.
Gravity
Earth - Shown when Blake made a rock clone in "No Brakes".

as for combinations, if you wanted to combine Fire and water to create steam then go ahead, but what type of Combinations are you thinking of?