GEMSTONE FIELD GUIDE
Aquamarine
A color variety of beryl, not a separate mineral species.
Aquamarine crystals with muscovite, NMNH 170272. Uncut museum reference specimen; not NumisTrends inventory.
Pale blue aquamarine crystals sit among muscovite blades. This is an uncut museum specimen, not a group of faceted stones.
Photo: Penland / Smithsonian National Museum of Natural History, CC0. · Source ↗ · CC0 1.0 · resized for the webA verified 3D specimen capture is not available for this entry. No generated stand-in is used.
AT A GLANCE
Start with the evidence.
A blue beryl identification is not automatically an aquamarine or natural-growth conclusion. Distinguish the host material, cause of color and any fracture filler.
- GIA — Aquamarine, Maxixe-type and synthetic blue beryl (2008) ↗
- GIA — Polymer-Filled Aquamarine (2009) ↗
- Refractive index (RI)
- 1.577–1.583
- Specific gravity (SG)
- 2.72 · typical
- Mohs hardness
- 7.5–8
typical interval
How to read this value
Published reference interval, not necessarily the two readings of every specimen and not an exhaustive identity boundary. Composition, orientation, wavelength, instrument and condition matter.
How to read this value
GIA's variety overview gives a typical 2.72 but no numeric tolerance. The broader 2.6–2.9 in GIA's technical beryl review is not substituted as a variety-specific range.
How to read this value
Scratch resistance, not toughness. This ordinal scale is not linear.
These are reference properties, not measurements of the pictured specimen. Reference images are educational—not NumisTrends sale inventory.
See the details and limitations ↓01 · IDENTIFY
Build a profile, not a guess.
Typical material-level reference; not a measurement, identification, origin, treatment determination, or grading result for any specimen.
Refractive index (RI)1.577–1.583
typical interval
Published reference interval, not necessarily the two readings of every specimen and not an exhaustive identity boundary. Composition, orientation, wavelength, instrument and condition matter.
Specific gravity (SG)2.72 · typical
GIA's variety overview gives a typical 2.72 but no numeric tolerance. The broader 2.6–2.9 in GIA's technical beryl review is not substituted as a variety-specific range.
Mohs hardness7.5–8
Scratch resistance, not toughness. This ordinal scale is not linear.
Birefringence0.005–0.009
Typical reference range; individual measured birefringence depends on the specimen and measurement orientation.
Optic characterUniaxial negative
CleavagePoor / indistinct basal cleavage
Species-level beryl property. Existing fissures and inclusions can matter more in practical durability.
Open a property for its scope and source. RI and specific gravity have no units. Mohs describes scratch resistance—not resistance to breaking. Do not scratch a stone to test it.
What can look similar?
Maxixe-type blue beryl
A different blue-color mechanism in beryl can resemble aquamarine.
How to investigate. A gemologist combines directional color with appropriate absorption spectra.
Do not deliberately expose it to heat or intense light to test fading.
Hydrothermal synthetic blue beryl
Its RI and density can overlap natural blue beryl.
How to investigate. Use growth features and spectroscopic evidence, not color or one matching reading.
The absence of fluorescence is not proof of natural growth.
02 · TESTS & ULTRAVIOLET
What a test can—and cannot—tell you.
Results depend on the specimen, instrument and method. This is a reference for understanding evidence, not a home authentication or treatment verdict.
UV reaction
- Long-wave UV
- Aquamarines from Brazil, Nigeria and Canada in the 2008 comparison study were inert under longwave UV.
- Short-wave UV
- Those aquamarine samples were also inert under shortwave UV.
The study's hydrothermal synthetic blue beryls were inert too, so this does not prove natural growth. Separately, some polymer-filled aquamarine fractures have shown chalky-white longwave fluorescence; that is not a universal host response.
Directional color and spectral comparison
Differences among aquamarine, Maxixe-type beryl and hydrothermal synthetic blue beryl.
Reference observation. The cited study found overlapping RI and density values; directional color and spectra supplied further distinctions.
Limit. A matching beryl reading does not establish growth origin or color origin.
Microscopy and infrared examination of fractures
Evidence of polymer introduced into surface-reaching fractures.
Reference observation. Published filled aquamarines showed flash effects and relief lines; infrared spectra supported polymer identification.
Limit. Inspect the host and filling separately. A clean-looking area does not establish that the entire stone is unfilled.
Real laboratory examples
Documented cases, not test results of the reference specimens shown on this page.
An aquamarine's unresolved iridescence
GIA examined a 40.27 ct aquamarine crystal whose internal shimmer changed with illumination angle. The authors proposed a structural explanation but did not establish its cause.
The takeaway. Record an observation separately from a proposed explanation; an unusual optical effect need not have an immediate diagnosis.
Use a qualified gemologist for identification work. Do not expose eyes or skin to UV sources, or perform scratch, heat, acid or solvent tests on a gemstone. Do not assume that an absent UV reaction rules a material out.
03 · TREATMENTS & CARE
Protect the stone you actually have.
Disclosed treatments, fractures and settings can change which cleaning methods are appropriate.
Use gentle warm-soapy-water cleaning. Protect against hard knocks and heat; liquid inclusions, fractures or filling change whether professional ultrasonic or steam cleaning is appropriate.
04 · SOURCES & SCOPE
Know where each fact comes from.
Original NumisTrends explanations with primary references. This is not a replacement for gemological training, a laboratory report, or the examination of your own stone.
Properties reviewed: 2026-09-07 · Identification notes reviewed: 2026-09-07
- gia.edu · aquamarine ↗
- gia.edu · winter 2019 analytical methods geographic origin determination gemstones ↗
- gem-a.com · JoG1955_5_4.pdf ↗
- gia.edu · aquamarine quality factor ↗
- gia.edu · aquamarine care cleaning ↗
NumisTrends is independent of GIA, Gem-A and the museums cited. A matching property cannot by itself establish identity, natural versus laboratory-grown origin, treatment, geographic origin, grade or value.