JACKSONVILLE, Fla - Think of Florida sand and it might all seem the same, but actually many unique varieties cover the state, with each type revealing its past.
In Flagler Beach, the sand is very different because it comes from a different source. The rusty-colored sand stands out from other quartz-covered Florida beaches.
Flagler County's beaches are known for striking pink and red colors that come from a nearby source of eroded coquina bedrock. Coquina bedrock is often exposed along the Matanzas Inlet shifting sands.
Currents play a role in eroding shorelines but some beaches disappear faster due to finer grains of sand while coarse sand helps beach material stay on the shore longer.
And the next time you see these dark stripes on a sandy beach, know they used to be at the tops of mountains.
Heavy minerals eroded from the Appalachian mountains over millions of years, flowed down streams and into the ocean. So if you look at the dark patches this is where the heavies are and they are mixed in with the quartz right now.
Sand collectors love these concentrated placers of black sand, deposited by currents and waves.
Coastal Geologist Jennifer Corr leads field trips at Mickler Beach. She is part of the Southeastern Geological Society and one of the speakers at this weekend's 2018 International Sand Collectors Society Symposium, which they call SanFest.
"Since the grains are more dense than the other materials, like quartz or shell, they are naturally heavy they collect and form a layer over time," Corr said.
After hurricanes, you can often spot the dark layer at the base of the dunes with these heavy minerals exposing rutile and zircon.
Members of the International Sand Collectors Society will meet to share their knowledge and enjoyment of sand with each other and anyone interested through Monday at the Morocco Shrine Auditorium.
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