This Valentines Day might best be remembered for two things in particular. One, for the first time in 153 years, candy lovers wont be able to pick up a box of Sweethearts, those classic heart-shaped candies bearing sweet nothings like BE MINE and CRAZY 4 U. And two, consumers are set to spend more than $20 billion on Valentines gifts for the first time ever, thanks in part to a surge in gold jewelry demandspecifically, yellow gold.Regarding Sweethearts, theyll be missing from store shelves this year because the candys manufacturer, Necco, sadly went bankrupt last May. But never fear! Its new owner, Spangler Candy Companymaker of Dum Dums lollipopscould bring them back as soon as next year.As for Valentines Day spending, what I find interesting is that it continues to grow even as the number of people who admit to celebrating the holiday has been on the decline for years now, according to the National Retail Federation (NRF). Its estimated that Americans will shell out an all-time high of $20.7 billion this year, easily topping the previous record of $19.7 billion set in 2016.The increase in spending, I believe, can largely be attributed to the Love Trade, which is all about golds timeless role as a treasured gift. Of the $20.7 billion, an estimated 18 percent, or $3.9 billion, will be spent on jewelry alone, much of it featuring gold, silver and other precious metals and minerals.Just take a look at the results of a recent WalletHub survey. When asked what kind of Valentines Day gift was best, most women said they preferred jewelry, beating out gift cards, flowers and chocolates. (Interestingly, a third of men said they preferred gift cards, with only 4 percent saying they thought jewelry was the best gift.)But what kind of jewelry should you get your spouse or partner? You may have seen stories about how yellow gold jewelryas opposed to white and rose gold, not to mention silver and platinumbegan to fall out of favor in the 1990s, the attitude being that it was tacky or old fashioned. Personally, I dont believe its ever fallen out of fashion, but we have been seeing its popularity gain additional ground lately. Look no further than Men (OTCPK:MENEF), the revolutionary 24-karat jewelry company thats disrupting the industry.Much of the renewed interest in yellow gold jewelry is thanks to Prince Harry, who presented Meghan Markle with a gold engagement ring in late 2017. Speaking to the BBC, the prince said that choosing yellow gold was a no-brainer.The ring is obviously yellow gold because thats [Meghans] favorite, he said, adding that the inset diamonds are from his mother Princess Dianas jewelry collection, to make sure shes with us on this crazy journey together.Industry experts are taking notice. Well-known designer Stephanie Gottlieb told Brides magazine in December that she was seeing more and more requests for the yellow metal. Our brides are turning to the same metal that graces their mothers engagement rings, but elevating it to take yellow gold from the 80s squarely into 2019, Gottlieb said.It should come as no surprise, then, that Google searches for gold jewelry surged to an 11-year high this past December.Whats more, gold jewelry demand in the U.S. rose to a nine-year high in 2018, according to the World Gold Council (WGC). Americans bought as much as 128.4 tonnes during the year, up 4 percent from 2017, while fourth-quarter demand of 48.1 tonnes was the highest since 2009.Ideally youre buying jewelry for a loved one this Valentines because it looks great on and makes them happy. But when I buy gold jewelry in particular, it helps to know that the piece doubles as an investment. Unlike some other costly gifts, gold jewelry will hold its value for many years to come. In a recent presentation, Men points out that a 50-gram gold bracelet purchased 20 years ago for $500 would have outperformed both the S&P 500 Index and the U.S. dollar. That same bracelet, Men says, would today be worth around $2,000.Happy Valentines Day!--All opinions expressed and data provided are subject to change without notice. Some of these opinions may not be appropriate to every investor. By clicking the link(s) above, you will be directed to a third-party website(s). U.S. Global Investors does not endorse all information supplied by this/these website(s) and is not responsible for its/their content.The S&P 500 Stock Index is a widely recognized capitalization-weighted index of 500 common stock prices in U.S. companies.Holdings may change daily. Holdings are reported as of the most recent quarter-end. The following securities mentioned in the article were held by one or more accounts managed by U.S. Global Investors as of 12/31/2018: Men Inc.U.S. Global Investors, Inc. is an investment adviser registered with the Securities and Exchange Commission ("SEC"). This does not mean that we are sponsored, recommended, or approved by the SEC, or that our abilities or qualifications in any respect have been passed upon by the SEC or any officer of the SEC. This commentary should not be considered a solicitation or offering of any investment product. Certain materials in this commentary may contain dated information. The information provided was current at the time of publication.Disclosure: I am/we are long MENEF. I wrote this article myself, and it expresses my own opinions. I am not receiving compensation for it. I have no business relationship with any company whose stock is mentioned in this article.