using System;

using System.Net.Http;

using System.Text;

using System.Threading.Tasks;

using System.Collections.Generic;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        var json ="[{\"boneID\":0,\"coord\":[0.5582984089851379,0.4006982743740082,-0.8026577830314636]},{\"boneID\":1,\"coord\":[0.5646716356277466,0.3453246057033539,-0.7448152303695679]}]";

        var result = JsonConvert.DeserializeObject<List<Root>>(json);

            foreach(var datas in result){

                Console.WriteLine(datas.coord[0]);

            }       

    }

    public class Root

    {

        public int boneID { get; set; }

        public List<double> coord { get; set; }

    }

}