The Orbit 6 pronged octahedral grey atom represents metal. It is used to represent sodium in the sodium chloride structure model and titanium in the rutile model and is also included in the Class Crystal Structure Models Set.
You can use these Genuine Cochranes of Oxford Orbit Molecular Model Parts to replace missing pieces or augment any of the Orbit Molecular Model Sets & Molecular Model Kits supplied by Indigo Instruments.