Sterling Silver is comprised on 92.5% pure silver and 7.5% of other metals, often copper. This additional metal gives sterling silver it's strength and can create tarnish on the sterling, which requires occasional polishing.
Fine Silver is 99.9% pure silver. It is softer than sterling silver and does not tarnish easily.
Rose Gold is composed of a percentage of yellow gold alloyed with silver and copper metals to create a soft pink colour. Depending on the amount of copper used, rose gold jewelry can vary in appearance from orange-yellow to dusky pink to red-orange. The components of true rose gold are approximately 75% gold, 22.5% copper and a small percentage of silver.
Gold Filled Despite how it sounds, gold-filled metal is not actually filled with gold. "Gold-filled" is simply an age-old term that became accepted in the jewelry industry. Today, gold-filled is a quality designation that's regulated by the Federal Trade Commission. To merit a "GF" stamp, the material must have a layer of gold that is at least 10-karat mechanically applied to a base metal; the karat gold layer must also be at least 1/20 (5%) of the item's total weight.