Gainesite is an exceptionally rare phosphate mineral discovered in complex granite pegmatites. It typically occurs as tiny, clear to milky-pale bluish lavender tetragonal crystals often perched on matrix surfaces with other rare pegmatite minerals. Due to its scarcity and limited distribution, it is highly sought after by advanced systematic mineral collectors.
Is this gainesite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch gainesite with a known reference. Gainesite sits at Mohs 4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: blue.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: pyramidal.
Often confused with
Gainesite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside gainesite
Minerals reported to co-occur with gainesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂BeZr₂(PO₄)₄·1.5H₂O
- Mohs hardness
- 4
- Density
- 2.94 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Tetragonal
- Crystal habit
- Pyramidal
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A very rare accessory mineral in a granite pegmatite
Where rockhounds find gainesite
Classic worldwide localities
- Nevel quarry, Newry, Oxford Co., Maine, USA
Field-hunting tip
Where it forms: A very rare accessory mineral in a granite pegmatite. If you start seeing roscherite, eosphorite, albite in float, you are in the right ground. Typical habit: pyramidal. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify gainesite?+
Where is gainesite found?+
Is gainesite safe to handle?+
What rocks look like gainesite?+
What minerals are found with gainesite?+
What kind of rock does gainesite form in?+
What is gainesite used for?+
Find gainesite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
