In the album some such as this one still look unfocused. But you can see the glass above it in sharp detail. I use Windows Paint to resize photos to bring overlarge ones to a manageable size and reasonable sharpness. However, your issue appears to be something other than the size. The background that you're using is causing your camera to focus on the non-marble parts of the view. Pick a neutral background without a lot of detail for the camera to focus on. A regularly recommended background is a gray t-shirt. If you keep picking up details on the material behind the marble and the marble stays blurry, then pull your camera back just a little to try to help the marble get into a comfortable focal range.