function [granite] = initializeGranite(args)

    arguments
        args.type          char    {mustBeMember(args.type,{'rigid', 'flexible', 'none'})} = 'flexible'
        args.density (1,1) double {mustBeNumeric, mustBeNonnegative} = 2800 % Density [kg/m3]
        args.K  (6,1) double {mustBeNumeric, mustBeNonnegative} = [5e9;   5e9;   5e9;   2.5e7; 2.5e7; 1e7] % [N/m]
        args.C  (6,1) double {mustBeNumeric, mustBeNonnegative} = [4.0e5; 1.1e5; 9.0e5; 2e4;   2e4; 1e4] % [N/(m/s)]
        args.x0 (1,1) double {mustBeNumeric} = 0 % Rest position of the Joint in the X direction [m]
        args.y0 (1,1) double {mustBeNumeric} = 0 % Rest position of the Joint in the Y direction [m]
        args.z0 (1,1) double {mustBeNumeric} = 0 % Rest position of the Joint in the Z direction [m]
        args.sample_pos (1,1) double {mustBeNumeric} = 0.775 % Height of the measurment point [m]
    end

    granite = struct();

    switch args.type
      case 'none'
        granite.type = 0;
      case 'rigid'
        granite.type = 1;
      case 'flexible'
        granite.type = 2;
    end

    granite.density = args.density; % [kg/m3]
    granite.STEP    = 'granite.STEP';

    % Z-offset for the initial position of the sample with respect to the granite top surface.
    granite.sample_pos = args.sample_pos; % [m]

    granite.K = args.K; % [N/m]
    granite.C = args.C; % [N/(m/s)]

    if exist('./mat', 'dir')
        if exist('./mat/nass_model_stages.mat', 'file')
            save('mat/nass_model_stages.mat', 'granite', '-append');
        else
            save('mat/nass_model_stages.mat', 'granite');
        end
    elseif exist('./matlab', 'dir')
        if exist('./matlab/mat/nass_model_stages.mat', 'file')
            save('matlab/mat/nass_model_stages.mat', 'granite', '-append');
        else
            save('matlab/mat/nass_model_stages.mat', 'granite');
        end
    end

end