Is there an ETF for diamonds?

Excuse me, I'm curious to know if there's an exchange-traded fund (ETF) specifically tailored for diamonds? As an investor looking to diversify my portfolio, I've been considering adding precious stones as an asset class. However, I'm not sure if there's a liquid and accessible way to invest in diamonds through an ETF, similar to how we can invest in stocks, bonds, or commodities through various ETFs. Could you enlighten me on this matter? Are there any unique challenges or considerations when investing in diamond-related ETFs, if they exist?