using System;

using System.Text;

public class Program

{

    public static void Main()

    {

        var specialMbytes = new byte[]{0xf0,0x9d,0x90,0xa6};

        var specialMstr =  Encoding.UTF8.GetString(specialMbytes);

        var specialMHex = BitConverter.ToString(specialMbytes).Replace("-",string.Empty);

        var normalized = Encoding.UTF8.GetString(specialMbytes).Normalize(NormalizationForm.FormKC);

        var normalizedHex = BitConverter.ToString(Encoding.UTF8.GetBytes(normalized));

        Console.WriteLine("UTF8 \"{0}\" (0x{1}) is normalized as \"{2}\" (0x{3})", specialMstr, specialMHex, normalized, normalizedHex);

    }

}