Purple Star Stardew Valley: The Hidden Power of Iridium Quality

The purple star marks iridium quality. This guide is scoped to Stardew Valley 1.6.15.24356 and separates ordinary crop-quality rolls from forage professions, fishing quality, fruit-tree age and Cask aging.

What iridium quality changes

• Its sell-price multiplier is 2× the normal-quality base value when that item uses ordinary quality pricing.
• Edible items generally restore more energy and health at higher quality.
• Gift quality modifies the friendship value of the recipient’s existing taste response; it does not turn a hated or disliked item into a liked one.
• Processing does not automatically copy an input star. Each machine follows its own output rules and Casks raise eligible artisan-good quality separately.

The local ordinary-crop formula

Let L be the effective Farming level and F the quality-fertilizer boost level: 0 for none, 1 for Basic Fertilizer, 2 for Quality Fertilizer and 3 for Deluxe Fertilizer.

goldRoll = 0.2 × (L / 10) + 0.2 × F × ((L + 2) / 12) + 0.01
silverRoll = min(0.75, 2 × goldRoll)

The game then uses separate random rolls in this order:

1. Only when F = 3, roll iridium at goldRoll / 2.
2. If iridium did not occur, roll gold at goldRoll.
3. If neither occurred, roll silver at silverRoll. With Deluxe Fertilizer, this remaining result is forced to at least silver.
4. Otherwise the crop is normal quality.

Therefore an ordinary unfertilized crop has an iridium probability of exactly 0%. Basic and Quality Fertilizer also do not create iridium-quality ordinary crops; that branch requires Deluxe Fertilizer.

Example at Farming level 10

These are calculated from the local formula and its sequential rolls; Basic Fertilizer does not split silver, gold and iridium into equal thirds.

When pursuing quality is worthwhile

Use higher quality for direct sale, eating, gifts that the recipient already accepts and displays such as the Grange Display. If the crop will become Jelly or Wine, input quality does not increase the initial artisan-good price, so compare the value of selling the starred crop directly against processing a normal-quality unit. Wine quality comes from optional Cask aging in a valid cellar rather than from the crop’s original star.