I got these for my kids (ahem, for myself) during my wooden toy obsession, but never opened them because of all the other wood toys already in rotation. 

These are NEW, were purchased from The Wooden Wagon.

Listing at $27, including shipping. 
These currently retail for $24 + shipping.


https://www.grimms.eu/en/products/river-pebbles
"
Building, stacking and finding just the right balance with these organic, round stone shapes is challenging and fun. Enrich small worlds of your own creation: add to a river (silk scarf), make a cave, present a stony landscape or build a cairn. Perfect in combination with our Elements: Fire (Art. No 10730/10780), Water waves (10720/10770) and Earth (10740/10790) and the other pepples (10058/10059).
4 pieces in shades of blue.
Materials: lime wood, non-toxic water based color stain.
Size: H = 2,5cm, L = 6-12cm."