Hobbies and Crafts Is buying a diamond necklace worth it? Is buying a diamond necklace worth it? Diamond jewelry is beautiful, special, and something that will last a lifetime— but it's also a good investment. Diamond jewelry, like many other physical commodities, tends to increase in price over time, regardless the state of the economy. Related Posts:A detailed look at various diamond clarity characteristics is included in the ultimate guide.How To Trade CommoditiesDoes diamond jewelry increase in value?How To Do you know if a diamond is real?