Cross section of a fossilized tree, the tree rings now filled with opal. Water filled cracks & the empty spaces of the petrified wood; the silica content in the water hardened into opal (can also change to chalcedony). This transformation turned it into fire opal, which is transparent/translucent in a warm range of colors: yellow, orange, orange-yellow or red. Opal is not a mineral - it is a mineraloid, a mineral like substance that does not demonstrate crystallinity.
Some of the design features included in this concept are incredibly popular additions for owners during a major refit, as well as when designing a new build; including the house sides and transom underwater lights, the beach deck aft, and the Hybrid EcoProp System enabling the yacht to cruise virtually noise and vibration free.