EDIT

show symbols with the units-header per record basis and kind of unit if needed

A quickly assembled list:

record basis

• DerivedUnit
• DnaSample: https://fontawesome.com/icons/dna?style=solid
• FieldUnit: https://fontawesome.com/icons/mountain?style=solid or https://fontawesome.com/icons/map-marker-alt?style=solid
• Fossil: https://fontawesome.com/icons/bone?style=solid
• HumanObservation: https://fontawesome.com/icons/eye?style=solid
• LivingSpecimen: https://fontawesome.com/icons/tree?style=solid
• MachineObservation: https://fontawesome.com/icons/binoculars?style=solid
• MaterialSample
• Media
• MovingImage: https://fontawesome.com/icons/film?style=solid
• Multimedia: https://fontawesome.com/icons/photo-video?style=solid
• Observation: https://fontawesome.com/icons/binoculars?style=solid
• OtherSpecimen
• PreservedSpecimen: https://fontawesome.com/icons/pagelines?style=brands or https://fontawesome.com/icons/leaf?style=solid
• SoundRecording: https://fontawesome.com/icons/microphone?style=solid
• StillImage: https://fontawesome.com/icons/image?style=solid
• TissueSample: https://fontawesome.com/icons/cut?style=solid,
• Unknown: DEFAULT-Symbol: https://fontawesome.com/icons/archive?style=solid ?? https://fontawesome.com/icons/cube?style=solid

kind of unit

• Culture: https://fontawesome.com/icons/flask?style=solid