Engineering the composition
A finished material is often a controlled mixture. Alloying adds elements to a metal; compounding combines a polymer with selected additives; a glass batch brings together ingredients for a particular network. Small changes can have important effects.
What changes?
Composition can alter strength, corrosion behaviour, colour, processing and many other properties. Mixing is not enough by itself: distribution and subsequent processing also matter. A glass-reinforced polymer, for example, has constituents with different roles rather than one completely uniform behaviour.
What the diagram leaves out
A familiar family name conceals many grades. Two products labelled stainless steel, nylon or silicone can differ in formulation and performance. Recycling mixed grades may require additional sorting or chemistry adjustments to meet the specification of the next use.
What to look for next
Look for the exact grade or formulation when performance is critical. An educational family description cannot replace a specification.
Follow a real material.
Aluminium
Light enough to carry. Adaptable enough to shape.
MetalsCarbon steel
Strength built from chemistry and structure.
MetalsStainless steel
A protective surface that renews itself.
MetalsCast iron
A heavy pan with a cast-in shape.
MetalsZinc
A layer that protects another metal.
MetalsLithium
A moving ion inside a rechargeable cell.
Elements & mineralsCobalt
Different chemistry, different job.
Elements & mineralsNeodymium
A small magnet can do a large job.
Elements & mineralsBorosilicate glass
Glass designed to move less with heat.
Glass & ceramicsPorcelain
Soft clay becomes a hard, dense vessel.
Glass & ceramicsCalcium carbonate
A mineral that becomes a filler, pigment or gentle abrasive.
Elements & mineralsSilica
The same chemistry can have different structures.
Elements & mineralsFollow the evidence
Original explanations informed by the sources below. Technical and industry sources support material behaviour; industry environmental marketing is not treated as a universal comparison. Read our editorial method.
- Aluminum Production and Processing ↗The Aluminum Association · Undated · Checked 2026-11-13
- Mineral Commodity Summaries 2026 — Aluminum ↗U.S. Geological Survey, National Minerals Information Center · 2026-05-27 (version 1.3) · Checked 2026-11-13
- What is steel? ↗World Steel Association · Undated · Checked 2026-11-13
- Raw materials ↗World Steel Association · Undated · Checked 2026-11-13
- General principles for selection of stainless steels ↗British Stainless Steel Association · Undated · Checked 2026-11-13
- Recycling ↗worldstainless · Undated · Checked 2026-11-13
- Sand casting ↗The Open University · 2017 · Checked 2026-11-13
- Zinc — element information, properties and uses ↗Royal Society of Chemistry · Undated · Checked 2026-11-13
- Mineral Commodity Summaries 2026 — Zinc ↗U.S. Geological Survey, National Minerals Information Center · 2026-05-27 (version 1.3) · Checked 2026-11-13
- Lithium — element information, properties and uses ↗Royal Society of Chemistry · Undated · Checked 2026-11-13
- Mineral Commodity Summaries 2026 — Lithium ↗U.S. Geological Survey, National Minerals Information Center · 2026-05-27 (version 1.3) · Checked 2026-11-13
- Technology Strategy Assessment — Lithium-ion ↗U.S. Department of Energy · 2023-07 · Checked 2026-11-13
- How Do I Recycle Common Recyclables ↗U.S. Environmental Protection Agency · Undated · Checked 2026-11-13
- Cobalt — element information, properties and uses ↗Royal Society of Chemistry · Undated · Checked 2026-11-13
- Mineral Commodity Summaries 2026 — Cobalt ↗U.S. Geological Survey, National Minerals Information Center · 2026-05-27 (version 1.3) · Checked 2026-11-13
- Neodymium — element information, properties and uses ↗Royal Society of Chemistry · Undated · Checked 2026-11-13
- Mineral Commodity Summaries 2026 — Rare Earths ↗U.S. Geological Survey, National Minerals Information Center · 2026-05-27 (version 1.3) · Checked 2026-11-13
- Borosilicate Glass ↗SCHOTT · Undated · Checked 2026-11-13
- Types of Technical Glasses ↗SCHOTT · Undated · Checked 2026-11-13
- Borosilicate glass: recycling guidance ↗North London Waste Authority · Undated · Checked 2026-11-13
- Holistic health: How ceramics and glass contribute to our physical and mental wellbeing ↗The American Ceramic Society · Undated · Checked 2026-11-13
- Rivalry and Dresden plates and quilts: European porcelain production ↗The American Ceramic Society · Undated · Checked 2026-11-13
- Quality of recycling: Towards a reference framework for the circular economy ↗European Commission Joint Research Centre · 2020 · Checked 2026-11-13
- Our Minerals ↗Omya · Undated · Checked 2026-11-13
- Oral Care Portfolio — Natural Calcium Carbonates ↗Omya · 2025 · Checked 2026-11-13
- Silica ↗Sibelco · Undated · Checked 2026-11-13
- Silica is safe — frequently asked questions ↗Evonik · Undated · Checked 2026-11-13
- Silica dust ↗UK Health and Safety Executive · Undated · Checked 2026-11-13