Borate, not quartz

Howlite is a calcium borate, not a type of quartz. Its official formula is Ca₂B₅SiO₉(OH)₅. The silica is part of the structure, but borate chemistry drives its behavior: lower hardness, light weight, and that helpful porosity for dyes.

Names & history

Discovered in Nova Scotia in the 19th century by the chemist‑geologist Henry How, the mineral was later named in his honor. You may also see antiquated references like “silicoborocalcite”—same mineral, less elegant name.

Evaporite‑adjacent

Howlite develops in borate‑rich sedimentary basins and altered volcanic ash deposits. Calcium‑bearing fluids mingle with boron and silica, precipitating nodular masses that can be the size of a fist—or a football.

Nodules first, crystals rare

Most howlite arrives as porous nodules with cauliflower or grape‑like surfaces. Well‑formed crystals are uncommon and typically small and tabular.

Veins that sketch themselves

Those black/grey “ink lines” are natural veinlets—thin fractures and micro‑voids stained by manganese/iron oxides that crisscross the white ground like pen on porcelain.

Palette

• Chalk to bone white — classic howlite body color.
• Dove grey — subtle mottling in denser pieces.
• Ink‑black veining — thin, wandering lines with occasional junctions.
• Dyed blues/greens — even color with darker veins (when colored).

Finish ranges from matte satin to a soft gloss; high‑gloss looks are usually aided by wax or resin sealers.

Pattern words

• Spiderweb — fine, interconnected black veining.
• Ink splash — thicker pools where veins meet.
• Porcelain — nearly vein‑free white for minimalist pieces.
• Turquenite — dyed blue/green howlite in turquoise style.

Photo tip: Neutral light (5000–5600K) keeps whites clean. A soft side light at ~30° gently lifts the veining without adding glare.

Vein reality check

Natural howlite veins look feathery and irregular, with soft edges and tiny offshoots. Painted lines look too sharp or end abruptly at the surface.

Pores & polish

Look for minute pores in matte areas. A sealed piece shows filled pores and a smoother, slightly waxy sheen.

Dyed tell‑tales

In colored howlite, dye can pool along veins or in surface pits. Under magnification you’ll see deeper color in micro‑cracks compared to the surrounding ground.

Magnesite

Another porous white stone often dyed blue. Key difference: magnesite (a carbonate) can effervesce in warm dilute acid; howlite (a borate) generally does not. Both are soft—handle kindly.

White “turquoise” / “White Buffalo”

“White turquoise” is mostly a misnomer; “White Buffalo” (from Nevada) is not turquoise either and is typically a magnesite/dolomite‑rich rock. Howlite is its own mineral—similar look, different chemistry.

Marble & dolomite

These can be bright white but show crystalline cleavage and react to acid. Howlite’s fracture is more ceramic/porcelain‑like.

Plastic & resin impostors

Lightweight plastics feel warmer to the touch and can show mold seam lines. A hot pin (do not try on finished jewelry!) is a lab trick—plastics mark or smell; minerals do not.

Turquoise (real)

Harder (Mohs ~5–6), higher heft, waxy luster, and different micro‑texture. If the blue is too uniform with perfect black lines, suspect dyed howlite.

Quick checklist

• Porcelain‑white ground with soft‑edged black veining?
• Light in hand; feels slightly chalky when unsealed?
• No fizz in dilute acid (on scrap)? Likely howlite.

Where it’s found

Classic occurrences include Nova Scotia (Canada) and parts of California, with additional deposits in the southwestern USA and Mexico. In many places it’s associated with borate‑rich sediments and altered volcanics.

In the workshop

Howlite’s light color makes it an excellent canvas for dyes. Jewelers also enjoy it natural for minimalist, black‑and‑white designs that read crisp and modern.

Everyday care

• Wipe with a dry or barely damp soft cloth; avoid long soaks.
• Keep away from perfumes, hair sprays, and household cleaners (they can stain or dull sealers).
• Store separately; quartz and steel can scuff its satin surface.

Jewelry guidance

• Best as pendants, earrings, beads. For rings/bracelets, use protective settings and mindful wear.
• If dyed, avoid prolonged sun/heat and solvents that may leach color.
• Matte metal finishes (brushed silver, blackened steel) make the white pop.

On the wheel

• Work cool and gentle; it’s soft and can undercut.
• Pre‑polish 600→1200→3k; finish with alumina on a soft pad for a satin glow.
• Seal with a thin, reversible microcrystalline wax if you want a higher sheen and stain resistance.

Ink & edge test (on scrap)

Touch a felt‑tip marker to an unsealed edge of rough or a drilling offcut: howlite’s pores grab the ink immediately. Sealed pieces resist/clean easily.

Spot the dye

Under 10×, look where veins meet. In dyed stones, the junctions look darker and color seeps a hair into micro‑cracks—nature doesn’t color outside the lines; dye sometimes does.