Pargasite

Pargasite is a calcic amphibole mineral. It’s usually dark green to black, and it tends to grow as prismatic crystals with two good cleavages that meet at about 56 and 124 degrees.

In hand specimen, pargasite looks blocky and solid rather than feathery like the fibrous amphiboles. It feels cool to the touch, as fresh-broken silicates typically do. Under dim indoor light it can appear nearly black, but under a brighter lamp a cleavage face may show a bottle-green flash.

Pargasite is easily mistaken for hornblende, which is reasonable because it belongs to the same amphibole family. A clean face helps: the amphibole cleavage planes meet at about 56 and 124 degrees, which becomes visible when the specimen is tilted slowly. It is more a collector mineral than a crystal-shop stone, and most pieces occur in matrix rather than as neat single crystals.

Pargasite got its first proper description in 1814, when Anders Gustaf Ekeberg worked it up from material collected at Pargas (Parainen), Finland. The name’s just the place name lifted straight off the map, which is how a bunch of amphiboles ended up being named in that era.

But it’s not just trivia. Pargasite sits in a slice of the amphibole series that petrologists actually lean on, and spotting it in a rock can clue you in on pressure, temperature, and fluid conditions during metamorphism. So even if a piece isn’t “display perfect” (maybe it’s a bit dull, edges scuffed, or the crystal faces aren’t all there), it still carries a real story.

You’ll run into pargasite in metamorphosed limestones and skarns, plus some mafic to ultramafic rocks. Finland is the classic name locality, but good collector material pops up in Canada, the Alps, and a handful of other metamorphic belts.

Pargasite commonly forms where hot fluids react with carbonate rocks, and skarns are the classic setting. When magma heats limestone or dolostone and drives silica and aluminum through the rock, amphiboles such as pargasite can grow alongside calcite, diopside, garnet and scapolite. Freshly broken surfaces of these rocks also produce fine dust, so a hand lens is best used on clean faces.

Compared to tremolite-actinolite, pargasite generally wants more aluminum and sodium in the recipe. So it shows up in higher-grade metamorphic settings, and that’s also why it’s annoying to ID just by gut feel. In the field, most people call it hornblende until they’ve got a microscope or chemistry to back it up, unless the area is already known for pargasite.

Color: Most pieces run dark green, greenish black, or nearly black. Thin edges can show a clearer green when backlit.

Luster: Vitreous on fresh cleavage faces, turning a bit dull on weathered surfaces.

Pick up a broken chip and rotate it under a single light source. Those two amphibole cleavages will flash like little mirrors and they meet at angles that aren’t 90 degrees. If you scratch it with a steel nail, you won’t get far, but a quartz point will bite it. And in hand, it often looks “blacker than it is” until you put it next to true opaque minerals like magnetite.

Pargasite is sometimes confused with these materials:

• Hornblende (common amphibole sold as “black amphibole”; cleavage angles and stubby prisms overlap a lot)
• Actinolite (dark green massive chunks, especially when it’s not obviously fibrous)
• Augite (dark pyroxene; can look the same until you check cleavage at ~90 degrees vs amphibole’s 56/124)
• Epidote (dark pistachio to near-black grains; people mix it up when pargasite is granular instead of prismatic)
• Dyed serpentine or dyed “jade” (green material with color sitting in cracks and along saw marks, used in cheap carvings)
• Black glass sold as “onyx” or “black stone” (uniform inky black, no cleavage, lighter feel than a real amphibole chunk)

Solid pargasite is safe to handle and put on display. But like any silicate, you don’t want to breathe in the dust if you’re cutting or grinding it (that fine powder gets everywhere).

If you’re going to lap or saw it, keep water running, make sure the area’s well ventilated, and wear a proper respirator that’s actually rated for fine particulates (not just a flimsy dust mask).

Rough/Tumbled: $15 - $250 per specimen

Cut/Polished: $20 - $120 per carat

Prices swing all over the place depending on the crystal form and whatever locality name is stuck on the label. A dark, chunky piece still sitting in matrix, the kind that feels heavier than it looks when you pick it up, is usually cheap. But a clean, transparent green bit you can actually facet? That price shoots up fast, because there just isn’t much of it.

Moderate — Scratch resistance: Fair, Toughness: Fair

It’s generally stable in a cabinet, but cleavage means sharp knocks can chip edges and pop off slivers.

Use & Storage

Store pargasite in a padded box or on a stable stand so the cleavages are not damaged. Avoid stacking it with quartz points, because quartz is harder and will scuff it over time.

Cleaning

1) Rinse with lukewarm water and a drop of mild dish soap. 2) Use a soft toothbrush to work around cleavage steps and matrix pockets. 3) Rinse well and pat dry, then air-dry fully before putting it back in a closed box.

Cleanse & Charge

Common cleansing methods in crystal practice include smoke, sound, or a quick rinse followed by drying. If moonlight is used, the stone should not be left afterward in a sunny window.

Placement

A desk shelf is fine, but don’t put it where it’ll get bumped. Angling one bright cleavage face toward a lamp makes the green show up way better than overhead room light.

Caution

Skip ultrasonic cleaners and any aggressive tumbling. Cleavage is sneaky like that, and it can take a clean, crisp edge and leave you with a little pile of chips before you even realize what happened. And don’t just toss it loose in your pocket next to harder stones, because they’ll knock it around and scuff it up fast.

Pargasite is mainly a collector and study mineral rather than a common crystal-shop stone. Most specimens are dark, dense and blocky, and many are sold still attached to matrix instead of as single crystals. Its name comes from the type locality, Pargas (Parainen) in Finland, a naming habit common among amphiboles described in that era. Transparent green material suitable for faceting is scarce, so cut stones are seldom seen.

In crystal traditions, pargasite is associated with the Heart, Throat and Root chakras, with Capricorn and Virgo, and with the elements Earth and Storm. Practitioners who use it tend to link its dark, heavy character with grounding and practical focus, and some pair it with meditation or breathwork. These are cultural beliefs, not proven effects, and they do not replace medical care for anxiety or illness.