How do I list a single item with variations?

[Stuffthings]

I sell one off pendants and offer them either on cord or chain. These options are different prices.
I can’t figure out how to list them without it still looking like the item is available with the option of cord or chain that hasn’t sold. 

[Serj94]

For example:

Create a product 'infinity pendant'

Add a new option 'bracing', inside variants indicate chain and cord.

For each variant add image, price.

If that case isn't appropriate, create 2 products for chain and cord. Add crosslinks to the pendant with different bracing.