Crystal
Cloudy pink, almost never in points — the stone people give each other rather than buy for themselves.
These are associations the community holds, not settled fact — the more a reading is shared, the bolder it sits.
Rose quartz is quartz that has gone pink, and for a long time nobody could say why. The current explanation, which took electron microscopy to reach, is that the colour comes from microscopic pink fibres — a mineral related to dumortierite — growing through the quartz in vanishingly small quantities. That is also why rose quartz is nearly always massive and cloudy rather than in clear points: the fibres that colour it are the same fibres that stop it growing clear. Well-formed pink quartz crystals exist, are coloured by something else entirely, and are rare enough to be a collector's item.
The association with love and reconciliation is where practice puts almost all of it, and unusually the tradition is fairly consistent across sources rather than being a modern invention layered over an older one — Roman and Assyrian workings in rose quartz survive, though what they were for is guesswork. Modern use tends towards the domestic: a piece by the bed, a piece given after an argument, a stone people are more likely to be handed than to choose.
It is worth saying that the "love stone" framing has been marketed hard, and that the gentleness attributed to it is at least partly the gentleness of the colour. That does not make it a bad stone to keep. It makes it a stone whose reputation is easy to explain without invoking anything unusual.
Readings practitioners have offered, ordered by how many recognise them. Take what serves, leave the rest.
Carried forward
Common in contemporary practice
Given rather than bought, in the same way turquoise is. The stone most often turns up in a household because somebody handed it over after a bad week — which means its reputation for softening things has a fairly ordinary mechanism attached to it already.
Carried forward
Common in contemporary practice
Sometimes described as fading in strong sunlight. This one is true: some rose quartz does lose colour under prolonged UV, so a piece kept on a south-facing sill will pale over years. Practitioners read the fading variously as depletion or as the stone having done its work.
Credit what you carry. Much of this comes from living traditions, and some of it from traditions that are closed — held by particular peoples and not offered for general use. Where you know whose practice a reading came from, name them; where you don't, say that too.