Focusing I'm trying to take pictures of jewelry and I can't get my pictures to focus, they're blurry.

What make and model camera? Which Sigma lens? Do you have autofocus turned on, both on the camera and the lens?

Try cleaning the lens contacts on the camera body and on the lens.
This maybe the problem, it is not making contact with the lens zoom motor.

in manual mode, will not try to focus itself, my be the manual auto switch is faulty, or the focus related mechanism not rotating the lens, open the lens carefully check the focus motor and gear set (engine is the technical term)

There are three main reasons for blurry pictures.
Pictures may come out blurry if they're not focused properly. If some objects are sharp and others are not, this may indicate focusing on the wrong subject. This is usually not a major problem with compact point&shoot cameras since they have such a wide field of focus that almost everything will be in focus anyway.
Subject motion. If moving objects blur while stationary objects remain sharp then the shutter speed is too slow to freeze the motion. Try switching to the sports mode, and/or add more light.
Camera motion. This is the most common cause. Set your camera on a table or other stable surface and use the self-timer to take a picture. Take another one while holding the camera. Compare the two on your computer.

There are several possible causes for blurry pictures.
1) Camera motion. If everything is blurry, it's most likely because the camera moved while the picture was being taken. Make sure your shutter speed is fast enough if you're handholding the camera (longer lenses require faster shutter speed). Alternatively, put your camera on a stable surface, such as a tripod or a tabletop.
2) Subject motion. If the subject is blurry but the background is sharper, then the subject may have moved while the picture was being taken. Use a faster shutter speed. Raise the ISO if needed. There are limits, of course. If you're trying to photograph a fast-moving object in the dark, you probably won't be able to.
3) Improper focus. If the subject is blurry but something else in the picture is sharp, then the camera probably focused on the wrong object. Move the focus selector to the subject you want in focus. Alternatively, center the viewfinder on the subject, press the shutter button halfway to lock focus, then reframe and shoot.
Without any more specific information as to what and how your pictures are blurry, I'm afraid the above is all I can give you.

The 55-200mm lens does not focus closer than 1.1 meters (3.6 feet). If the subject is too close, then the autofocus tries and fails to focus or keeps trying (and squeaking). Either way, you won't be able to take a picture. In manual focus, you can take a picture but it will be out of focus and blurry.

Every lens has a minimum focus distance, closer than which it will not focus. Some lenses focus closer than others. It's a matter of design; making lenses focus closer makes them larger, heavier, and more expensive.

If you want to take close-ups, you have several options. You can buy close-up adapters that fit onto the front of a lens. You can buy a special close-up lens ("macro" or "micro" lens). You can buy extension tubes to fit between the camera and a lens.

There's a diopter control near the viewfinder to adjust the viewfinder to your eye. Try adjusting that while peering into the viewfinder and try to get the focus brackets and the data at the bottom of the viewfinder into focus.

your camera's lense is clear? try clean it with suitable cleaner for lense. If still not working, check your user manual for setting

There are three main reasons for blurry pictures.
Pictures may come out blurry if they're not focused properly. If some objects are sharp and others are not, this may indicate focusing on the wrong subject. This is usually not a major problem with compact point&shoot cameras since they have such a wide field of focus that almost everything will be in focus anyway. However, make sure the macro/far switch is set to the appropriate position for your picture.
Subject motion. If moving objects blur while stationary objects remain sharp then the shutter speed is too slow to freeze the motion. Try switching to the sports mode, and/or add more light.
Camera motion. This is the most common cause. Set your camera on a table or other stable surface and use the self-timer to take a picture. Take another one while holding the camera. Compare the two on your computer.

How old is the set? If picture is really very blurry, Try adjusting 'focus'. You can find this conttrol generally at the rear of the set. Otherwise,. if you know solid state electronics, Check the Focus control on the FBT. It is also possible that the CTR Base is faulty. Replacing this helps.