Amulet of Arcane Sight

An ever-burning coal from a campfire, trapped inside a transparent, polished sphere of crystal, about the size of chestnut. A creature attuned to the Amulet of Arcane Sight may close their hand around the crystal to see the presence and flow of magic around them, as if they had cast detect magic. The spell remains in effect so long as the amulet remains pressed against the skin of the creature's closed palm. The spell reveals the weave of magic as a spectrum of coloured light, visible to the wearer even if they would not normally be able to see. The particular colour, shade, and intensity of the vision gives the wearer clues to the nature and origin of the magic.

School of Magic. Under the sight of the amulet, the magic of each arcane tradition appears as a unique colour. The wearer's bias and personal interpretation of colours and their meanings means that no two creatures will perceive the same spell in the same way, and some may associate schools of magic to different colours than those suggested below. Many wizards may view necromancy as black, divination as violet, and evocation as an electric blue. These associations may shift overtime, but to the uninitiated, they appear as follows:
The protective spells of Abjuration magic are blue, ranging from cyan to deep indigo;
Conjuration spells are yellow, from pale gold to brilliant, shining brass;
Divination magic ranges from tarnished silver to pale grey, or even a transparent but no less detectable aura;
Spells of Enchantment appear in a spectrum of gentle, rosy pink to deep lilac;
Evocation magic is red, from pastel scarlet to rich burgundy;
Workings of Necromancy range from pallid green to a viridian so dark as to be almost black;
Transmutation is orange, from a washed out watercolour sunset to dark rust.
Illusions, by their very nature are harder to accurately interpret, and may seem to be of a different school of magic entirely. Compare the Spellcasting level of the spell's creator to the proficiency bonus of the amulet's wearer. If the spellcasting level is a higher number, the chance that the spell will appear as a different school equals 5 times the difference between the two numbers. It otherwise appears as a spectrum, dominated by shades of violet;

Power / Spell Level. The power of a spell is hinted at by the intensity of the visible aura, with more powerful works and higher level spells appearing in vivid hues, with paler pastels for cantrips and less powerful magic.

Nature. Most spells will appear as a glowing cloud of coloured energy, but some may take more defined shapes. For example, a hold person spell may appear as pale, pink chain, wrapping itself around the effected target, and blindness/deafness appears as a spectral, green binding, circling a target's head.

Origin. Magic that hails from worlds beyond the material plane may have signs of their origin within their aura. A spell cast by a fiend is of a darker hue than that of a mortal wizard, and may appear more viscose or oily, while the works of celestial beings may be bright white, with the barest flickers of colour. The spell's of a denizen of the shadowfell may seem washed out, like sun-bleached paint, while elven magic from the feywild may be speckled with motes of light like tiny, fluttering stars.

Notes: Detection, Necklace, divination