Code snippet that needs reviewing?

I have a segment of code that’s supposed to put floats into a FloatBuffer to create a small voxel; however, whenever I try to render it, it comes out as a flat plane.
Could anyone help me with this?


	public float[] voxelVertices(float x, float y, float z) {
		float xx = x * 0.2f, yy = y * 0.2f, zz = z * 0.2f;
		return new float[] {
				//	x,			y,				z
				// Top quad
				xx + 0.1f,		yy + 0.1f,		zz + 0.1f,
				xx - 0.1f,		yy + 0.1f,		zz + 0.1f,
				xx - 0.1f,		yy + 0.1f,		zz - 0.1f,
				xx + 0.1f,		yy + 0.1f,		zz - 0.1f,
				// Bottom quad
				xx + 0.1f,		yy - 0.1f, 		zz - 0.1f,
				xx - 0.1f,		yy - 0.1f,		zz - 0.1f,
				xx - 0.1f,		yy - 0.1f,		zz + 0.1f,
				xx + 0.1f,		yy - 0.1f,		zz + 0.1f,
				// Front quad
				xx + 0.1f,		yy + 0.1f,		zz - 0.1f,
				xx - 0.1f,		yy + 0.1f,		zz - 0.1f,
				xx - 0.1f,		yy - 0.1f,		zz - 0.1f,
				xx + 0.1f,		yy - 0.1f,		zz - 0.1f,
				// Back quad
				xx + 0.1f,		yy - 0.1f, 		zz + 0.1f,
				xx - 0.1f,		yy - 0.1f, 		zz + 0.1f,
				xx - 0.1f,		yy + 0.1f, 		zz + 0.1f,
				xx + 0.1f,		yy + 0.1f, 		zz + 0.1f,
				// left quad
				xx - 0.1f,		yy + 0.1f, 		zz - 0.1f,
				xx - 0.1f,		yy + 0.1f, 		zz + 0.1f,
				xx - 0.1f,		yy - 0.1f,		zz + 0.1f,
				xx - 0.1f,		yy - 0.1f,		zz - 0.1f,
				// right quad
				xx + 0.1f,		yy + 0.1f, 		zz + 0.1f,
				xx + 0.1f,		yy + 0.1f,		zz - 0.1f,
				xx + 0.1f,		yy - 0.1f, 		zz - 0.1f,
				xx + 0.1f,		yy - 0.1f, 		zz + 0.1f};
	}