The Stone That Cracked Before It Left Your Factory

"Stone crack ho gaya." Jaipur mentioned it. "CZ cloudy aa raha hai." Mumbai said the same. "Sab kuch sahi tha, phir bhi stone damage." Rajkot, same story.

Different cities, different teams, same complaint.

🔍 THE HIDDEN COST OF CRACKED STONES

Here's what we've learned from years of these conversations: the stone itself is rarely the problem.

CZ isn't expensive. But setting labour is. The karigar who spent 20 minutes placing that stone, the QC person who inspected the tree, the polisher who prepped the piece all that time walks out the door when a stone cracks.

And then there's the business cost nobody talks about:

• Teams start avoiding stone-in-place orders — too risky, too unpredictable

• Quotes go higher — to cover expected rework

• Orders move to competitors — who've figured out how to do it reliably

💡 THE REAL PROBLEM ISN'T TECHNIQUE

When stones crack, the instinct is to blame process. Burnout wasn't right. Cooling was too fast. Operator made a mistake.

But here's the thing: most alloys aren't designed for stone-in-place casting. They're general-purpose red gold alloys that manufacturers adapt for stone work.

The alloy doesn't know stones are present. The cooling protocol doesn't account for thermal stress on set stones. You're forcing two things together that weren't designed to work together.

Adjust kar lo only works until it doesn't.

✨ AN ALLOY DESIGNED FOR THE JOB

BH111RC is an 18KT pink-red gold master alloy from Legor (Italy) that was formulated specifically for stone-in-place casting. Not adapted. Formulated.

What makes it different:

✓ Documented cooling protocol — remove flask immediately, dip bottom in cold water, ventilate 15 minutes, then warm water quench. Alloy and procedure designed together.

✓ 60°C melting window — solidus 840°C, liquidus 900°C. Forgiving temperature control, less overheating risk.

✓ Very high grain refinement — fine grain structure means smoother surfaces, less polishing, fewer post-cast issues.

✓ High deoxidation — cleaner melt, reduced porosity, better yield.

📊 THE NUMBERS

Specification Value

Composition Cu 87%, Ag 11%, Zn 2%

Hardness (as cast) 160 HV

Melting range 840–900°C (60°C window)

Karat range 9KT, 14KT, 18KT

Applications Stone-in-place, open systems, plain casting

⚠️ WHAT THIS WON'T FIX

I should be honest: a better alloy won't save a broken process.

If your burnout cycle is inconsistent, stones will still fail. If temperature control is all over the place, results will be unpredictable. If the cooling protocol isn't followed exactly, thermal shock will crack stones regardless of alloy.

Par agar aapka process already solid hai if you're doing everything right but stones still crack unpredictably then the alloy is likely the missing piece.

💬 AVOIDING STONE-IN-PLACE ORDERS?

If your team hesitates when stone-set orders come in quoting high to cover risk, or quietly steering customers toward plain designs it might be worth a conversation.

We can send a trial sample with the complete Legor stone-in-place protocol. Cast your most challenging tree. Compare results.

Reach out: help@preciousalloy.com | +91 22 6101 4444