The pink one — cloudy rather than transparent, and dyed imitations are common.
Every continent — the commonest mineral in the crust3 references
Rose quartz is quartz coloured by microscopic fibrous inclusions of a borosilicate mineral, and that inclusion cloud is why it is almost always translucent-to-cloudy rather than clear. Genuinely transparent pink quartz exists and is a different, much rarer thing usually sold as pink quartz rather than rose quartz.
The cloudiness is the identification. Rose quartz's colour is distributed unevenly through the mass in wisps and patches, palest at the edges of a piece and strongest where the stone is thickest. Dyed white quartz and dyed glass both do the opposite: colour concentrated in surface fractures, an even flat pink through the body, or a suspiciously vivid hot pink that no natural rose quartz reaches.
The colour also fades. Prolonged direct sunlight will visibly pale a rose quartz over months, which is worth knowing before putting a piece on a south-facing windowsill. A stone that has been sitting in a shop window for a year is often paler than the same material fresh from the ground.
Massive rose quartz · Star rose quartz · Pink 'lavender' quartz
Establish which of these you are holding before judging it. A genuine piece read against another reference's rules will look wrong when it is not.
These apply to this model and not to the rest of Quartz. Work them alongside the maker's general checks, not instead of them.
Look into any surface fracture under a loupe. Dye pools in fractures and along grain boundaries, so a dyed stone shows lines of concentrated colour where the material is broken and pale material between them. Natural rose quartz shows the opposite pattern — colour in the body of the stone, indifferent to where the cracks are.
Natural rose quartz has a soft internal cloudiness with faint directional streaks, from the inclusions that cause the colour. Dyed quartzite looks granular and sugary instead, and glass looks perfectly clean apart from bubbles.
Whatever the colour, it must scratch glass and resist a steel blade. Dyed marble and dyed calcite are sold as rose quartz surprisingly often, and both are soft enough for a knife to bite — and both fizz in vinegar.
Cheap and abundant. Tumbled pieces sell for a few dollars; a large well-coloured carved piece reaches the low tens.
An orientation for honest, unrestored condition — never an appraisal, and never a quotation.
Lovenhall StoneThe tests tell you what it is. The instrument reads a photograph and offers a name to start from — then hands you back to the tile and the coin, which are what settle it.