It depends on what kind of jewelry. The concept of jewelry is very big, and some of them are not very valuable. Some of them are really valuable. It depends on specific things. Like some common pearls and agates, they are all jewels and are not expensive. If there is a rare big diamond in the world, its value must be extremely high, not to mention priceless. For example, the following:

Sangxi diamonds are priceless, originated in India and considered to belong to the Mughal dynasty. Sancy diamond, discovered in 1570, is the largest diamond with symmetrical features. This pear-shaped yellow diamond weighing 55.23 carats is now collected by the Louvre Museum in France.

Cullinan diamond is called the largest gem-grade diamond found so far. This stone is even called the "Star of Africa", and it is said that interested people will spend about 2 billion dollars to get it.

Hope diamond, sometimes called "French blue", is one of the most famous gems in the world. It is said that its clarity is one of the highest in any gem in its series, and its valuation is also very high, about $200 million.