Identification guide · Silicate Minerals
How to Identify Sunstone
Sunstone is usually orange, red, and golden with a vitreous luster and is transparent. It has a Mohs hardness of 6.5. It scratches glass and a steel knife and cannot be scratched by a steel file. Its streak is white. It is most often confused with Quartz, Natrolite, and Spessartine; the tests below separate them.
Sunstone identification checklist
| Color | Orange, Red, Golden, Pink, Colorless | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
| Transparency | Transparent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 6.5 | It scratches glass and a steel knife and cannot be scratched by a steel file. |
| Streak | White | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Perfect in two directions | |
| Fracture | Uneven to conchoidal | Broken surfaces show smooth, curved, shell-like scoops. |
| Specific gravity | 2.65 | Ordinary rock-like heft (specific gravity about 2.65), similar to quartz. |
| Crystal system | Triclinic |
Extra tests for Sunstone
Glass check. Sunstone shares a glassy luster and conchoidal fracture with man-made glass. Glass sits near Mohs 5.5 and often contains round gas bubbles, so a hardness test and a hand lens separate them.
Sunstone look-alikes and how to tell them apart
Both sit near Mohs 6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Sunstone vs Quartz →
Sunstone is harder (Mohs 6.5) than Natrolite (Mohs 5.5), so Sunstone will scratch Natrolite and not the other way round. It is about as hard as window glass: a knife barely marks it, while a steel file (Mohs 6.5) will. Sunstone vs Natrolite →
Both sit near Mohs 6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Sunstone vs Spessartine →
Both sit near Mohs 6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Is my Sunstone real?
- Hardness: real Sunstone sits at Mohs 6.5. Glass imitations are about 5.5, so genuine Sunstone scratches glass while a glass fake cannot.
- Bubbles: round gas bubbles under a 10x loupe mean glass or resin, never a natural stone.
- Color: dyed material concentrates color in cracks and pores; look for pigment collecting at the edges of fractures.
- Temperature: natural crystals feel cool and take longer to warm in your hand than plastic or resin.
Field tips
- Look for a glittering metallic shimmer, called aventurescence, that flashes as the stone is tilted.
- Feldspar cleavage in two directions and hardness near 6 to 6.5 help confirm the identification.
- Tiny copper or hematite platelets create the sparkle, so distinguish it from simple orange feldspar.
Sunstone identification FAQ
How can you tell if a rock is Sunstone?
Check the color (orange, red, golden, and pink), the vitreous luster, a Mohs hardness of 6.5 and a white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Sunstone?
Sunstone has a Mohs hardness of 6.5. It scratches glass and a steel knife and cannot be scratched by a steel file.
What is the difference between Sunstone and Quartz?
Sunstone (Mohs 6.5, vitreous luster) and Quartz (Mohs 7, vitreous, greasy on fracture surfaces luster) look alike, but hardness, streak and heft usually separate them. See the full Sunstone vs Quartz comparison for a side-by-side table.
How do I know if my Sunstone is real?
Real Sunstone matches the hardness listed above, shows no round gas bubbles under magnification, and does not concentrate dye in cracks. Glass and resin fakes fail at least one of those checks.
Is Sunstone worth anything?
Entry-level Sunstone specimens sell for around $10, typical collector pieces about $90, and premium examples $700 or more depending on size, quality and locality.
What color is Sunstone?
Sunstone is most often orange, red, golden, and pink. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
