| CRYSTALS | Repeating three-dimensional arrangements of atoms, molecules or ions in the form of amethyst. beryl, garnet, opal, tourmaline (8) |
| CRYSTALLATTICE | Three-dimensional arrangement of atoms inside a diamond, say |
| POLYMER | A substance with a molecular structure formed from many identical small molecules or other units bonded together |
| CLUSTERS | Aggregations of galaxies or bound atoms/molecules; bunches of grapes; groups of consonants; or, networks of computers (8) |
| CHEMIST | Occupation involving investigating atoms, molecules and elements (7) |
| NONONSENSE | Repeating three points after a double negative is sensible (2-8) |
| ZIPZAPZOP | Improv warm-up that involves clapping while repeating three similar sounds |
| OPAL | Siliceous gem with kaleidoscopic colours said by Pliny to encompass the blue of sapphire, the green of emerald, the purple of amethyst, the red of ruby and the yellow of topaz (4) |
| SCARAB | Sacred coleopteran of the ancient Egyptians; or, a piece of amethyst, carnelian, lapis lazuli, turquoise or other mineral carved in the form of said chafer as an amulet, gem or seal (6) |
| ISOMER | Each of two or more compounds with the same formula but different arrangements of atoms (6) |
| LATTICE | A regular periodic arrangement of atoms, ions, or molecules in a crystalline solid |
| CHAIN | Bonded sequence of atoms forming a molecule; or, a series of connected events, house purchases, daisies, mountains or metal links (5) |
| ISOMERISM | Property of having the same formula but a different arrangement of atoms |
| WELLS | Brickwork, dry-stone or wavy "crinkle-crankle" structures; defences of interlocked shields; fortifications; or, arrangements of tiles at the beginning of play in mah-jong (5) |
| CHIGNONS | Arrangements of long hair in rolls or knots at the back of the head (8) |
| CYCLE | Concisely removes harmful ions in series of events that are regularly repeated |
| STERIC | Involving the arrangement of atoms in space (CITERS anag.) |
| AZALEA | Iggy, byname of Amethyst Kelly, Australian singer/ songwriter and rapper born in 1990 (6) |
| NONMETAL | Element incapable of forming positive ions in water (8) |
| ANODE | ___ ray (stream of positive ions in a gas-discharge tube) |
