sedimentary
Expanded Clay Pebble
Lightweight Expanded Clay Aggregate (LECA)
Hardness: 3-5 (Mohs), Color: Brown to reddish-brown, Luster: Dull/Earthy, Structure: Vesicular/Porous internal structure with a hard outer shell, Specific Gravity: 0.3-0.7 (often floats)
Identified More sedimentary →
Explore Expanded Clay Pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-5 (Mohs), Color: Brown to reddish-brown, Luster: Dull/Earthy, Structure: Vesicular/Porous internal structure with a hard outer shell, Specific Gravity: 0.3-0.7 (often floats)
Formation & geological history
Formed by heating common clay to approximately 1200 degrees Celsius in a rotary kiln. The gases expand the clay into thousands of small bubbles, creating a honeycomb structure.
Uses & applications
Extensively used in hydroponics and aquaponics as a growing medium. Also used in construction for lightweight concrete, insulation, and water filtration systems.
Geological facts
It is one of the most popular hydroponic substrates because it provides excellent aeration and drainage while remaining chemically neutral and pH stable.
Field identification & locations
Identify by its spherical shape, lightweight feel, and porous interior. It is most commonly found in garden centers, construction sites using lightweight fill, or hydroponic setups.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary