Hovlitas

Hovlitas

Howlite • calcium borate mineral Formula: Ca2B5SiO9(OH)5 • System: monoclinic Hardness: ~3.5 • SG: ~2.53 • Luster: from matte to semi-glassy (polished – satin) Appearance: chalk white to grayish white with spiderweb black/gray vein patterns Porous and easily dyed (common turquoise imitation)

Howlite — porcelain-white calm with ink sketch veins

Howlite is a soft, porcelain-white borate known for ink-colored, spiderweb veining. In nature, it forms cauliflower-shaped nodules polished to a soothing, bone-white luster. It is also open in character: porous, light, and "thirsty"—which is why it so easily takes dyes that it is often invited on stage to "play turquoise." (Think of it as a stand-in who knows the lines perfectly.)

🧪
What it is
Calcium borate mineral occurring as nodules and rare tabular crystals; popular for beads and pendants
🕸️
Recognizable style
From matte to satin white with spiderweb black/gray vein patterns; evenly takes dyes up to bright blues/greens
🧼
Care summary
Avoid soaking, perfumes, and strong cleaners; clean gently; keep away from harder stones

Identity and names 🔎

Borate, not quartz

Howlite is a calcium borate, not a variety of quartz. Its official formula is Ca2B5SiO9(OH)5. Silicon is part of the structure, but the borate chemistry determines behavior: lower hardness, lightness, and that useful porosity for dyes.

Names and history

Discovered in Nova Scotia in the 19th century thanks to chemist-geologist Henry How; the mineral was later named in his honor. Sometimes in old sources it is called "silicoborocalcite"—the same mineral, just a less catchy name.

Trade tip: Dyed blue howlite is widely sold as "turquenite". It's not turquoise—just convincingly "acting" like it from a distance.

Where it forms 🧭

Hydrous environment

Howlite forms in borate-rich sedimentary basins and altered volcanic ash deposits. Calcium-rich solutions mix with boron and silicon, depositing nodular masses from fist to soccer ball size.

Nodules first, crystals rare

Howlite is most often found as porous nodules with a cauliflower or “grape cluster” surface. Well-formed crystals are rare, usually small and tabular.

Veins that “draw themselves”

Black/gray “ink lines” are natural veins—thin cracks and microcavities stained with manganese/iron oxides, crossing the white base like drawn on porcelain.

In short: calm basins, patient solutions, and a natural tendency to absorb dyes well later.

Palette and pattern glossary 🎨

Palette

  • From chalk to bone white — classic howlite base color.
  • Dove gray — subtle mottling in denser pieces.
  • Ink-black veins — thin, winding lines with junction knots.
  • Dyed blues/greens — even background with darker veins (when dyed).

Surface ranges from matte satin to smooth softness; highly glossy appearance usually achieved with wax or resin sealers.

Pattern terms

  • Spiderweb — fine, interconnected black veining.
  • Ink splash — thicker spots where veins meet.
  • Porcelain — almost veinless, for minimalist pieces.
  • Turquenite — dyed blue/green howlite in turquoise style.

Photo tip: Neutral light (5000–5600 K) maintains a clean white. Soft side light at ~30° angle subtly highlights veins without glare.

Physical and optical details 🧪

Property Typical range / note
Chemistry Ca2B5SiO9(OH)5 (calcium borate)
Crystal system Monoclinic; usually massive/nodular
Hardness (Mohs) ~3.5 (softer than a knife blade; harder than a fingernail)
Relative density ~2.53 (light in hand, though "rocky")
Cleavage / fracture Poor to indistinct; uneven to sub-conchoidal fracture
Luster From matte to semi-glassy; polished/sealed – satin
Transparency Invisible; thin edges may be barely transparent
Optics RI ~1.586–1.605 (biaxial); birefringence low (~0.015–0.020)
Fluorescence Often weak white to bluish white under UV light
Porosity High — absorbs dyes and oils; surface sealers are common
Simple translation: beautiful, light, and "absorbent"—handle it like delicate matte ceramics, not like a granite countertop.

Under the loupe 🔬

Vein authenticity check

Natural howlite veins look fluffy and irregular, with soft edges and fine branching. Drawn lines are too sharp or abruptly end at the surface.

Pores and polish

In matte areas, you will see fine pores. A sealed piece will show filled pores and a smoother, somewhat waxy luster.

Traces of dyeing

In dyed howlite, dyes can concentrate color in veins or surface pores. At higher magnification, color in microcracks will be deeper than in the surrounding matrix.

Similar and misleading names 🕵️

Magnesite

Porous white stone, often dyed blue. The main difference: magnesite (a carbonate) can fizz in warm diluted acid; howlite (a borate) usually does not react. Both are soft—handle gently.

“White turquoise” / “White Buffalo”

“White turquoise” is usually a misnomer; “White Buffalo” (from Nevada) is also not turquoise—typically it is magnesite/dolomite-rich rock. Howlite is a separate mineral: similar appearance but different chemistry.

Marble and dolomite

May be very white but show crystalline cleavage and react with acid. Howlite’s fracture is more ceramic/porcelain-like.

Plastic and resin fakes

Light plastics feel warmer to the touch and may have mold seams. The hot needle test (do not do this on finished jewelry!) in a lab reveals plastic by smell or mark; minerals do not react.

Turquoise (genuine)

Harder (Mohs ~5–6), heavier, with a waxy luster and different microstructure. If the blue is too uniform with “perfect” black lines, suspect dyed howlite.

Quick checklist

  • Porcelain-white base with soft-edged black veining?
  • Light in hand; untreated feels slightly chalky?
  • No fizzing in diluted acid (on a cut)? Likely howlite.

Find spots and notes 📍

Where found

Classic localities: Nova Scotia (Canada) and some California sites; additional deposits in the southwestern USA and Mexico. Often associated with borate-rich sediments and altered volcanics.

In workshops

The light color of howlite makes it an excellent “canvas” base for paints. Jewelers also like the natural look—for minimalist, black-and-white designs that appear clean and modern.

Labeling idea: “Howlite — calcium borate, white with spiderweb veining (natural or dyed)”—this makes everything clear to the reader.

Care and lapidary notes 🧼💎

Daily care

  • Clean with a dry or slightly damp soft cloth; do not soak for long.
  • Keep away from perfumes, hair sprays, and household cleaners (they can stain or damage sealants).
  • Store separately; quartz and steel can scratch the satin surface.

Jewelry guidelines

  • Best for pendants, earrings, beads. For rings/bracelets, choose protective settings and wear carefully.
  • If dyed, avoid prolonged sun/heat and solvents that can pull out color.
  • Matte metals (brushed silver, blackened steel) highlight the whiteness.

On the wheel

  • Work cool and gently; it is soft and can “dent” near veins.
  • Pre-polish 600→1200→3k; finish with aluminum oxide on a soft pad for a satin glow.
  • For greater stain resistance and shine, seal with a thin, reversible microcrystalline wax.
Exposure tip: Place natural white-with-veins howlite next to a necklace of dyed blue beads. Next to it, it’s instantly clear what is “turquenite.”

Practical demonstrations 🔍

Ink and edge test (on a cut piece)

Touch a marker to the edge of unsealed raw material or drill scrap: howlite pores instantly “grab” the ink. Sealed pieces repel/easily wipe off.

Recognize dyes

Look under a 10× loupe where veins intersect. In dyed stones knots look darker, and the color slightly “seeps” into microcracks—nature doesn’t “color” beyond lines, dyes sometimes do.

A little joke: howlite is the gemology world's study ceramic—a neutral palette, beautiful lines, and yes, it likes a good “glaze.”

Questions ❓

Is howlite the same as turquoise?
No. Howlite is a borate, often dyed to imitate turquoise (turquoise is copper and aluminum phosphate). Similar appearance, but very different chemistry and hardness.

Can my bracelet stain?
If unsealed and worn with lotions or perfumes, howlite can “absorb” color. A thin sealant helps; also helps to put on jewelry after cosmetics.

How to tell painted from natural?
Look for color concentration in pores/veins, unnaturally uniform background or bright shade, unusual for natural turquoise. A cotton swab, slightly moistened with water (on an inconspicuous spot), should not remove color from well-fixed dye or sealed surface.

Is it suitable for everyday wear?
Yes—with gentle habits. It is soft (Mohs ~3.5), so the easiest are earrings and pendants; rings will benefit from protective settings and periodic resealing.

Why choose natural howlite?
Black on white spiderweb aesthetics – clean, modern, and goes with everything—no paint needed.

Return to the blog