Stonehenge Doesn't Have a Density—But Its Stones Do

Clarifying the Question

Stonehenge as a monument has no single density—it's an arrangement of separate stones with air gaps. Density (mass/volume) applies to materials, not structures.

Stone Densities

• Sarsen Stones (silcrete): ~2.65 g/cm³ (similar to sandstone/quartzite)
• Bluestones (dolerite, rhyolite, volcanic tuff): 2.7–3.0 g/cm³
• Lintels: Same as uprights (sarsen)

Structural "Bulk Density"

If you calculated mass of all stones ÷ volume of the entire monument footprint (including empty space), you'd get a meaningless low number (~0.1 g/cm³) that varies with layout reconstruction.

Why It Matters

Stone density informed transport logistics: 25-ton sarsens from 25 km away, 2-4 ton bluestones from 225 km (Wales). The builders understood material properties—shaping, mortise/tenon joints, and stability calculations imply sophisticated empirical engineering.