Please help me get my answers

Got this from a web search.

925 is sterling silver meaning that is contains 92.5% Silver and 7.5% of other metals. [Always look out for the numbers 925 on the hallmark - a small stamp made into the surface of the jewellery - e.g. on the inside of a ring]

So why not us pure Silver for jewelry? Because the other metals are harder, Sterling Silver becomes much more resistant to damage, scratching or bending than if you were to use pure silver (not bending was very important why rich people used to eat from silver cutlery)

Gold Jewellery is not .925 it is typically sold as 9, 18 or 24 kt (karat). Which is a measure of purity. 24kt is pure (100%), 18kt is 75%, and 9kt is only 37.5% (i.e 9/24). It is alloyed with other metals to give different colours "white gold", "yellow gold" "rose gold" (rose gold is high in copper for example)

Prices of gold and silver vary every minute of every day on the commodities market, but once it's made into jewellery there are many other price factors (depends on the design, the exclusivity etc)

Sterling silver contains 92.5% pure silver and 7.5% of copper and other metals. The process of alloying these metals with pure silver improves its hardness and durability. The introduction of copper and other metals in sterling silver jewelry brings about allergic effects on the skin.

Sterling silver jewelry is stamped in various ways such as 'Sterling', '925', 'ster', 'sterling silver' to indicate its quality.