What type of camera lens this is?

I inherited this lens from a late auntie's estate. Can anybody tell me what sort of lens it is and what sort of camera it belongs with?

Unfortunately I'm fairly confident it won't fit my DSLR which is a Nikon D3100 but i'm just curious to find out what camera this lens belongs to and how much it's worth.

That lens will mount on any Minolta 35mm camera and new Sony DSLRs. It won't work with your 3100.

It's worth about 30 or 40 bucks if the glass is in good condition.

The D3100 can use any Nikkor AF-S lenses.

Trying to cross match between different camera makers has never worked well and even when adapters are used, attempting to use the cameras light meter can either be problematic or fail all together.

Decades ago, Minolta made excellent cameras and lenses, but were never able to compete with Nikon and Pentax at the time. In 1988, Canon entered the arena and became a force, moving Pentax out of the way (Pentax took too long to convert to bayonet mounted lenses)

Taylor is both right and wrong. Your Sigma 60-200mm zoom was made with a Minolta "SR" mount and will work on Minolta manual focus 35mm film cameras. However, it will NOT work on a Sony DSLR nor will it work on the Minolta Maxxum auto focus 35mm film cameras. Minolta abandoned the "SR" mount for the "A" mount on the Maxxum 7000 in 1985 and continued using the "A" mount on their short-lived DSLR cameras. When Sony bought the DSLR line from Konica-Minolta, Sony kept the "A" mount.