Crystals are becoming increasingly popular for their metaphysical and healing properties. With so many crystal types available, you may be wondering – how do you identify the type of crystal you have? There are some key features to look for when determining your crystal type.
Look at the crystal’s color
One of the easiest ways to narrow down your crystal is by its color. While some crystals come in a range of hues, the color can give you clues as to what mineral it contains. Here are some of the most common crystal types by color:
| Amethyst | Purple |
| Citrine | Yellow to golden brown |
| Rose quartz | Pink |
| Green quartz | Green |
| Smoky quartz | Brown to gray |
| Sodalite | Deep blue |
| Red jasper | Red |
| Clear quartz | Colorless |
As you can see, many crystals are variations of quartz but contain additional minerals that lend them color. The color can be a great starting point for identifying your crystal type.
Examine the crystal’s structure
In addition to color, the overall shape and structure of your crystal can offer clues. Here are some distinguishing structural characteristics of common crystals:
Clear quartz – Six-sided prism terminated by a six-sided pyramid at each end. May containvarious inclusions.
Amethyst – Same hexagonal structure as quartz but in shades of purple.
Rose quartz– Hexagonal quartz in pale to deep pink. Often opaque with a milky translucence.
Smoky quartz – Hexagonal structure with very dark brown to black color. Translucent.
Citrine – Pale yellow hexagonal quartz crystals. May also form as clusters.
Apophyllite – Octagonal pyramidal or tabular crystals often in clusters.
Calcite – Rhombohedral, often double-terminated. Strongly fluorescent under UV light.
Kyanite – Long bladed crystals with a flat diamond-shaped cross section.
The basic shape and symmetry of the crystal faces can help narrow down the possibilities. Quartz varieties in particular exhibit a distinctive hexagonal pattern.
Observe the crystal’s luster and texture
The way light interacts with the crystal surface, known as luster, provides more identifying factors. Here are some telltale signs of different luster types:
Vitreous – Glassy, transparent luster. Seen in quartz and calcite.
Waxy – Surface appears smooth and wax-like. Common in jasper and agate.
Pearly – Shows an iridescent play of light. Found in moonstone.
Silky – Soft fibrous look aligned in one direction. Occurs in satin spar gypsum.
Dull or earthy – Absence of luster. Typical of kaolinite and hematite.
The texture of the crystal surface is also helpful for identification. Here are some typical textures:
Smooth – No visible surface irregularities. Seen in mica, apophyllite.
Granular – Coarse gritty texture like sugar. Common in turquoise, lapis lazuli.
Banded – Parallel stripes or ribbons of color. Found in agate, onyx, sardonyx.
Drusy – Covered in tiny crystal points. Occurs in quartz and amethyst geodes.
Fibrous – Dense mass of thread-like crystals. Occurs in satin spar, chrysocolla.
The luster and texture gives you visual clues about the crystal structure, composition, and conditions under which it formed.
Do hardness and clevage tests
Testing some physical properties of the crystal can further confirm its identity:
Hardness – Try scratching the crystal with a steel nail, glass, copper coin, and pocketknife. Comparing where you start to see scratch marks narrows the hardness range.
Cleavage – See if the crystal fractures cleanly along flat planes by carefully striking it with a hammer. The cleavage angles and easiness of breaking reveal the internal structure.
Quartz has a hardness of 7 and no cleavage, while calcite has a hardness of 3 and perfect rhombohedral cleavage. Mica has a hardness of 2.5-3 and basal cleavage in thin sheets.
Identify any inclusions
Many crystals contain inclusions of other minerals, fluids, or gases trapped during their formation. These inclusions provide valuable clues to the crystal’s identity. Here are some notable inclusions and the crystals they appear in:
Rutile – Long black striations. Occurs in quartz and tourmaline.
Hematite – Metallic gray-black spots. Common in quartz.
Goethite – Reddish brown needles. Found in quartz.
Chlorite – Green inclusion threads or patches. Seen in amethyst.
Pyrite – Metallic cubic crystals. Occurs in quartz and calcite.
Enhydros – Moving bubbles. Evidence of trapped water or gas in quartz.
Inclusions essentially provide a snapshot into the crystal’s origins. They demonstrate the conditions and minerals present during its formation.
Consider the crystal’s environment
Finally, the geologic environment where the crystal was found provides one last clue. Here are some typical formation environments of common crystals:
Quartz – Igneous, metamorphic, and sedimentary rocks; veins; geodes.
Calcite – Sedimentary environments like limestone and marble caves.
Gypsum – Evaporite deposits in sedimentary rocks.
Mica – Igneous and metamorphic rocks like granite and schist.
Apophyllite – Basalt cavities and voids in volcanic rocks.
Knowing where a crystal originated tells you a lot about how and when it formed. This can help narrow down what type it may be.
Do diagnostic tests
For definitive identification, there are some diagnostic tests that can be done:
Streak test – Rubbing the crystal on a porcelain plate reveals its streak color, an important distinguishing characteristic.
Acid test – Place a drop of dilute acid like vinegar on the crystal. Bubbles indicate carbonate minerals like calcite and dolomite.
Fluorescence – Viewing under UV light reveals if the crystal fluoresces. Useful for scheelite, fluorite, and calcite.
Specific gravity – Measuring the crystal’s density differentiates light minerals from heavy ones.
Chemical analysis – Techniques like X-ray diffraction can definitively identify the crystal’s chemical composition.
These advanced tests give you the most definitive answer to your crystal’s identity. They may be performed by gemologists or professional mineralogists.
Conclusion
Identifying an unknown crystal type involves a multi-step process. First examine its observable properties like color, shape, luster and texture. Perform simple physical tests of hardness and cleavage. Inspect any inclusions that may be visible. Finally, consider the source location and, if needed, do diagnostic testing. With careful observation and deductive reasoning, you can zero in on the type of crystal you found. Proper identification is key to understanding the energetic and healing qualities of your crystal. By following these steps, you will unlock your crystal’s secrets.