Quartz, but with souvenirs

Quartz is silicon dioxide. As it grows from silica-rich solutions, it can trap "guests" — other minerals, tiny droplets of the same solution, or even gas chambers. If the guest keeps its shape, it is a solid inclusion; if a droplet — a fluid inclusion; if an inclusion — a cavity in the crystal shape called a negative crystal.

Why some inclusions align

Many needles are epitaxial — they grow in preferred directions dictated by the quartz lattice. Thus rutile often intersects at neat ~60°/120° angles, and tourmaline rods tend to run parallel to the quartz c-axis.

Captured during growth

As quartz faces advance, they can overgrow existing microcrystals or trap a droplet of the surrounding solution. This forms quartz with rutile and tourmaline needles — the needles came first, and quartz "glassed" them in transparent silicon dioxide.

Pauses and renewals

Quartz often grows in pulses. A break leaves a dusty layer; renewed growth creates a phantom — a faint outline of the previous crystal preserved inside the new one.

Settling and healing

Tiny cracks can admit chlorite- or iron-rich solutions that "paint" the fissure. Later, quartz heals that seam, preserving dendrites, "mosses," or confetti-like flakes as a permanent artwork.

Fluid time capsules

Fluid inclusions are droplets of ancient water (sometimes oil) trapped during growth. In two-phase inclusions, you can see liquid + gas bubble; gently warm the stone — and the bubble will jump.

Negative crystals

These are cavities mimicking crystal shapes — often tiny quartz-shaped voids. They may have a thin liquid film or bubble and look like floating tiny facets.

Colors are brought by "guests"

Chlorite gives green, hematite — red, goethite/lepidocrocite — orange, rutile — golden. Even colorless quartz becomes dramatic when guests "bring paint."

What you can see

• Hairs / needles — golden rutile, black tourmaline, green actinolite.
• Confetti — shiny hematite or lepidocrocite plates.
• Moss / gardens — chlorite clouds, earthy oxides ("lodolite").
• Fireworks — star-shaped, crosshatched sagenite networks.
• Phantoms — faint internal triangles recreating the outer peak.
• Enhydros — a moving bubble in a clear cavity.
• Negative crystals — tiny, faceted voids — like quartz within quartz.

How light plays

Needles catch side light and "blink"; plates flash like tiny mirrors; chlorite softens the interior, adding depth. A black cardboard behind the crystal increases contrast; a point light source "brings inclusions to life."

Photography tip: Use a single small light source at about a 30° angle and move the stone, not the light. You'll see how the needles "light up" when the angle is right.

Rutile vs. actinolite

Rutile needles — mirror-bright and often meet at neat angles; actinolite looks silky, fibrous, sometimes slightly curved with a softer sheen.

Phantoms, not scratches

Phantoms are inside and move together with the stone when you tilt it. Surface scratches catch light only at certain angles and "stay in place" relative to you.

Fluid play

Warm the stone in your palm: the bubble in the two-phase inclusion enlarges/reduces or shifts. Under long-wave UV light, some hydrocarbon inclusions glow bluish-white.

Negative crystals

Look for perfectly faceted cavities with sharp edges — miniature quartz shapes inside. A tiny bubble along one edge is a great sign.

Needle orientation

In many crystals, needles run parallel to the c-axis (the crystal's length). Rotate the specimen — if the needles "activate" in bands, you see orientation and light play.

Edge inspection

Where inlays reach the surface, polishing may cause a slight "slip" (undercut). This is normal — just a reminder to handle edges gently.

Crack-painted quartz

Thermally cracked quartz, into whose cracks paint is poured. At 10× magnification, you will see a branching network of cracks, evenly colored — completely different from real mineral grains.

Glass "strawberry"

Glass with copper glitter (aventurine glass) is smooth, bubbly, and soft. Natural strawberry quartz shows tiny plates/needles inside the quartz and has ~7 Mohs hardness.

"Super Seven" marketing

Brand names promise many species in one stone; in reality, most have a few iron oxides and occasionally rutile. Enjoy the beauty — but write on the label what you see.

Dendrites vs. "garden"

Dendrites are tree-shaped Mn/Fe oxides along a plane; "garden" are volumetric mossy lumps (chlorite). One is a flat "drawing," the other a tiny terrarium.

Surface coatings

External oxide coatings can mimic inclusions. Check edges and breaks — if the "inclusion" wipes off or flakes, it was a coating.

Quick checklist

• Inclusions show depth and parallax when you tilt the stone.
• Mineral shapes are consistent (needles, plates, cubes), not paint blobs.
• Quartz hardness (7) and flaky chips on fresh breaks.

World highlights

• Brazil (Minas Gerais and Bahia) — quartz with rutile and tourmaline inclusions; lush "gardens."
• Pakistan and Afghanistan — actinolite "green hairs" in quartz; excellent tourmaline rods.
• The Alps and Himalayas — chlorite phantoms; negative crystals; crystalline tips.
• South Africa (Messina) — rare blue ajoite/papagoite inclusions.
• Arkansas, USA — transparent crystals with interesting titanium oxide features.
• Madagascar — picturesque lodolites and hematite "fire" inclusions.

What varies by locality

Needle type, density, and color palette depend on the rock's chemistry and temperature. Alpine specimens are usually especially transparent with vivid phantoms; Brazilian "gardens" feature mossy volume; Pakistani material has silky green fibers.

Daily care

• Quartz is hard (Mohs 7), but the tips split — handle like a fine needle.
• Use lukewarm water + mild soap + soft brush; rinse and dry.
• Avoid ultrasonic/steam devices for enhydros and heavily included stones.

Exposure and storage

• Side lighting at about 30° and a dark background "bring out" inclusions.
• Keep away from high heat — fluid inclusions can expand and stress the crystal.
• Store separately from softer gems (quartz usually wins scratch "competitions").

Lapidary tips

• Orient the dome so that needles cross the apex or a bubble sits in the center.
• Perform careful pre-polishing (up to 3k–8k) before final polishing with cerium oxide (or another oxide) on soft pads; light pressure helps avoid the "orange peel" effect.
• Before shaping the cabochon, stabilize inclusions reaching the edge; consider bevels to protect exposed areas.