u/53FROGS_OPALAUCTIONS

Alright, let’s have some fun.

I’m running a true no reserve auction on this thin carved Coober Pedy opal. Starting at $1 USD, highest bid takes it. All bids in USD.

Specs:
8.40 carats
27 x 25 x 2 mm
Body tone N7
Brightness B3
Solid natural carved opal from Coober Pedy

This is a thin carving at around 2 mm thick, so please check the measurements before bidding. Thin opal has plenty of good jewellery uses when it is set appropriately. It can be used as a lightweight carving, in low profile settings, or easily turned into a doublet. The important thing is that it is stable solid opal, not cracked material.

Auction rules:
Bidding starts at $1 USD
Minimum bid increment is $5 USD
Highest valid bid at close wins
Auction ends 72 hours from posting
Tuesday, 19 May 2026 at about 8:30 PM Queensland time
Sniper rule: any bid in the last 5 minutes resets the timer to 5 minutes
All bids must be placed in this thread. Bids elsewhere or by DM won’t be counted.

Shipping:
Worldwide available
I’ll cover shipping on this one

Payment:
Payment within 48 hours via PayPal

I’ll reply to bids in thread so it’s easy to follow.

If you’ve never bought opal before, this is a good way to dip your toes in without overthinking it.

I run the 53Frogs shop on Opal Auctions for those who know me.

Let’s see where it lands.

i get asked this all the time
“how thin can i go and still call it a solid?”

after cutting tens of thousands of opals, you develop a feel for what’s ideal vs what’s just acceptable
but putting that into clear words has always been tricky for me

so i finally sat down and put numbers to it

i’ve sold over 130k stones over the years, so i pulled a sample of data on 8,679 solid cut opals and mapped thickness vs size

a few things stood out:

most commercial solid opals end up around 3–5mm thick, regardless of size

the 20–25% rule is real, but it’s a minimum survival line, not where most stones land

the biggest mistakes happen in the 5–15mm range (shortest side), where people push stones too thin

quick takeaways if you’re cutting:

under 10mm → don’t go below ~2mm for rings

under 15mm → don’t go below ~2.5mm for rings

earrings/pendants can go thinner

when in doubt → aim for ~3mm

you can go thinner… but you need a reason, and you have to be very careful cutting the profile to keep the stone stable and settable

this graphic shows where most stones sit, where the outliers are, and where things start getting risky

curious where others land on this, especially setters

Alright, let’s have some fun.

I’m running a true no reserve auction on this Lightning Ridge opal. Starting at $1 USD, highest bid takes it. All bids in USD.

Specs:
1.75 carats
15 x 8 x 3 mm
Body tone N5/N6
Brightness B3

Solid natural opal from Lightning Ridge. Nice rolling colour with reds, greens and flashes of gold across the face.

Auction rules:
Bidding starts at $1
Minimum increments $5

Highest valid bid at close wins
Auction ends 48 hours from posting (approx 2pm AEST 30 April)
Sniper rule: any bid in the last 5 minutes resets the timer to 5 minutes

Highest valid bid at close wins

All bids must be placed in this thread. Bids elsewhere or via DM won’t be counted.

Shipping:
Worldwide available
I’ll cover shipping on this one

Payment:
Payment within 48 hours via PayPal

I’ll reply to bids in thread so it’s easy to follow.

If you’ve never bought opal before, this is a good way to dip your toes in without overthinking it.

I run the 53Frogs shop on Opal Auctions for those who know me.

Let’s see where it lands.