How can you tell the value of gems?

Some gemstones are desired for their sparkle and rarity while others have practical applications in engineering and electronic components. Laura and Antonia look at different ways gems can be made in the lab, how valuable they are and consider how you could potentially make a lot of money from them.

Fact check:

• The composition of sapphire and ruby
• A list of valuable diamonds
• The most expensive lab grow gems
• News about growing bigger gems from small ones already used as jewellery
• A research article on the same thing as above
• Synthetic sapphire
• More on synthetic sapphire
• Yet more on synthetic sapphire, in a YouTube video