I went to spend 2 weeks in Cuba in March and came back with few coral fossils found on the beach at Trinidad (city, not the island).
Some of them are very light so I was able to pack few of them in my baggage. They are also very easy to drill through so I had to try to growth an orchid. Seems working well as this Spathoglottis hardingiana was install 2 months ago now and it’s showing new growth.

I use a piece of hygrolon to growth the orchid and bring water from the bottom of the fossil.