(NEXSTAR) – Costco has added yet another precious metal to its website’s online offerings: 1-ounce silver coins.

The coins, produced by the Royal Canadian Mint, feature an image of a maple leaf on the front and the likeness of King Charles III on the reverse. Each is advertised as containing 1 Troy ounce of 99.99% pure silver.

Costco is selling the coins in 25-count “tubes” at around $629 per tube. (Exact prices were not available on the Costco site as of Friday morning, but social-media users and other online reports appeared to indicate varying amounts.) Costco members can purchase up to five “tubes” in a one-time transaction, according to the Costco website.

The coins appeared to be unavailable on the site as of Friday morning. A companion offering — 1-ounce 24k gold coins from the Royal Canadian Mint, priced at over $2,000 per coin — were listed as “sold out” on Costco’s site.

The silver coins, which debuted only recently, are the latest precious metals offered exclusively to Costco members since the company began selling gold bars in September 2023. In a December earnings call, Costco CFO Richard Galanti said members had purchased “over $100 million” worth of gold bars in the preceding quarter alone — and on Thursday, he indicated silver was starting strong, too.

“[E-commerce] showed strength in several areas, led by sales of gold, and, very recently, silver,” Galanti said during the earnings call.

But reviews for the silver coins weren’t as strong as those for the gold bars. On the Costco website, numerous customers pointed to problems with the packaging or the seal of the tubes, alleging the coins were spilled during shipping. Several said the coins were scratched or damaged as a result.

A representative for Costco was not immediately available to comment on the alleged issues, though Costco did respond to one of the reviews on its site, indicating its customer service team could assist with “any outstanding concerns.”

Reviews for the 1-ounce gold coins, also produced by the Royal Canadian Mint, appeared more positive, though none of the reviewers appeared to have actually received the product as of Friday.

Consumer interest in precious metals has likely risen in recent years amid concerns over inflation or economic instability, experts say. Owning a tangible asset, some buyers think, could be a safeguard against what they believe to be more volatile investments.

“If someone’s going out to buy gold, that means they think that there’s some type of instability at the structural level of the market and/or the government itself,” David Wagner III, the head of markets and equities at Aptus Capital Advisors, told the Associated Press shortly after Costco began offering its gold bars in 2023.

In the same article, however, he argued that gold has not always kept up with inflation, and said he considers it “one of the worst things that you can ever own.”

The Commodities Future Trading Commission also urges buyers to be wary of precious metals and especially the claims they may hear in TV or online advertising.

“The truth is gold and other precious metals are highly volatile and past performance is not a good predictor of future returns,” the commission says.