I am currently faceting a beautiful all natural Heliodor gemstone. It is going to be a round brilliant design. I have seen in recent years Heliodor being marketed as Yellow Emerald. It's my opinion that it is just a marketing gimmick. Both Heliodor and Emerald are part of the Beryl family of gemstones. The family members of Beryl are Emerald (green), Heliodor (yellow), Morganite (peach to pink), Bixbite (one of the world's rarest gemstones is red) and Goshenite (clear). They are all beautiful gems.
I am also in the process of faceting a beautiful lab created Ruby. It is a 9mm cushion cut gem. Lab created gemstones have the same physical and optical properties of natural gems. The advantages of lab created gemstones are lower price and they are also usually cleaner gems, meaning less inclusions than the natural gem material.
Both of these gemstones will look great in a piece of jewelry such as a ring or a pendant.