You already have 14k = sapphire in your grid (from clue 10).
Combine this with clues 6 and 9 like this:
Clue 6: topaz -> -> ruby
Clue 9: silver -> -> 14K/sapphire
Notice that the right sides of these two inequalities are the same step distance from the left, and notice that the right side options of ruby and sapphire are in the same category.
Since ruby and sapphire can never be in the same row, and since they are a fixed distance from topaz and silver, then topaz and silver cannot be in the same row.