Each of these shell vases is a sculpture that represents the sea!
White Shell Vase with Flower Arrangement by Dorothy's Creative Designs.
An inspirational idea from Design Happy. A nautilus shell vase holds an Air Plant Display.
I think this vase is the White Large Ceramic Shell Vase by Privilege, sold at Bellacor. Seen at Lighthouse Interiors. It's a pedestal style ceramic shell vase.
Sandstone Nautilus Shell Vase from Wayfair's Shell Vase Collection.
And a Ceramic Shell Vase from Wayfair's Ceramic Shell Collection where you have a few great choices, including a Ceramic Shell with Succulents (below).
This Ceramic Shell Vase is also available in turquoise.
For more ideas and clam shell planters, check out these posts:
Decorating with Seashell Planters
Succulent Shell Planter Ideas