Fold 1 First Reader
Dig, Dig, Dig!A red gem! Once, we had just two.
The rare stone set
Six books about the same six rare stones. Each fold goes deeper than the one before, and every fact in all six comes from the same fact bank.
Watch a page grow up
For many years, only two painite crystals were known. Drag the slider to read all six versions, word for word from the books, then try another fact.
Fold 2 Read Together
Hello, Rare Stones!Fold 2 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 3 Early Reader
Rare Stones: Hidden in the GravelFold 3 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 4 Explorer
Rare Stones: Secrets of the Rarest GemsFold 4 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 5 Field Guide
Rare Stones: A Field GuideFold 5 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 6 Deep Dive
Rare Stones, Unfolded: Why Some Minerals Are So Hard to FindFold 6 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 1 First Reader
Dig, Dig, Dig!A red gem sits in a rock.
Fold 2 Read Together
Hello, Rare Stones!Fold 2 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 3 Early Reader
Rare Stones: Hidden in the GravelFold 3 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 4 Explorer
Rare Stones: Secrets of the Rarest GemsFold 4 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 5 Field Guide
Rare Stones: A Field GuideFold 5 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 6 Deep Dive
Rare Stones, Unfolded: Why Some Minerals Are So Hard to FindFold 6 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 1 First Reader
Dig, Dig, Dig!A lamp hit a blue gem. It lit up!
Fold 2 Read Together
Hello, Rare Stones!Fold 2 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 3 Early Reader
Rare Stones: Hidden in the GravelFold 3 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 4 Explorer
Rare Stones: Secrets of the Rarest GemsFold 4 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 5 Field Guide
Rare Stones: A Field GuideFold 5 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 6 Deep Dive
Rare Stones, Unfolded: Why Some Minerals Are So Hard to FindFold 6 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 1 First Reader
Dig, Dig, Dig!A cut gem! Not on the list!
Fold 2 Read Together
Hello, Rare Stones!Fold 2 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 3 Early Reader
Rare Stones: Hidden in the GravelFold 3 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 4 Explorer
Rare Stones: Secrets of the Rarest GemsFold 4 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 5 Field Guide
Rare Stones: A Field GuideFold 5 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 6 Deep Dive
Rare Stones, Unfolded: Why Some Minerals Are So Hard to FindFold 6 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 1 First Reader
Dig, Dig, Dig!One gem? We have just one!
Fold 2 Read Together
Hello, Rare Stones!Fold 2 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 3 Early Reader
Rare Stones: Hidden in the GravelFold 3 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 4 Explorer
Rare Stones: Secrets of the Rarest GemsFold 4 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 5 Field Guide
Rare Stones: A Field GuideFold 5 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 6 Deep Dive
Rare Stones, Unfolded: Why Some Minerals Are So Hard to FindFold 6 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 1 First Reader
Dig, Dig, Dig!A blue gem, dug at one spot!
Fold 2 Read Together
Hello, Rare Stones!Fold 2 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 3 Early Reader
Rare Stones: Hidden in the GravelFold 3 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 4 Explorer
Rare Stones: Secrets of the Rarest GemsFold 4 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 5 Field Guide
Rare Stones: A Field GuideFold 5 is still being written. Its version of this fact appears here when the book passes its checks.
Fold 6 Deep Dive
Rare Stones, Unfolded: Why Some Minerals Are So Hard to FindFold 6 is still being written. Its version of this fact appears here when the book passes its checks.
The facts behind it: For many years, only two painite crystals were known to science. Once, people knew of just two painite crystals. 2 published sources
The facts behind it: Gem red beryl grew in cracks in rhyolite, a volcanic rock, in Utah's Wah Wah Mountains. The Ruby Violet mine in Utah's Wah Wah Mountains is the only known commercial source of gem-quality red beryl. 2 published sources
The fact behind it: Benitoite glows bright blue under shortwave ultraviolet light. 2 published sources
The facts behind it: The first known taaffeite was a gem that had already been cut, noticed in 1945 among stones from a Dublin jeweller. Laboratory tests showed the stone was a mineral no one had described, and it was named taaffeite after Count Edward Taaffe, who noticed it. 2 published sources
The facts behind it: Kyawthuite is known from a single crystal, found near Mogok, Myanmar. Scientists have just one kyawthuite crystal to study. 2 published sources
The facts behind it: Tanzanite's only known source is the Merelani Hills near Mount Kilimanjaro in Tanzania. Tanzanite is mined in just one place, the Merelani Hills of Tanzania. 2 published sources
Fold 1 · First Reader · River gravel
Dig, Dig, Dig!
- Ages
- 4–6
- Trim
- 6 × 9 in
- Pages
- 24
- Words
- 101
Meet six rare stones: a red gem once known from just two crystals, a blue gem that lights up under a lamp, and a gem known from one tiny crystal. Every word is a short word to sound out or a common sight word, except three words taught with pictures on the Words to know page: gem, rock and blue. Source notes for adults sit at the back.
Fold 2 · Read Together · Topsoil
Hello, Rare Stones!
- Ages
- 6–8
- Trim
- 8.5 × 8.5 in
- Pages
- 32 planned
- Words
- 150–260 planned
A picture book to read together. An adult reads the lines and questions while the child joins in.
Fold 3 · Early Reader · Clay layer
Rare StonesHidden in the Gravel
- Ages
- 8–10
- Trim
- 6 × 9 in
- Pages
- 32 planned
- Words
- 350–550 planned
Short sentences for children starting to read on their own, with a picture on every reading page and useful new words taught first.
Fold 4 · Explorer · Bedrock
Rare StonesSecrets of the Rarest Gems
- Ages
- 10–12
- Trim
- 8 × 10 in
- Pages
- 40 planned
- Words
- 1,500–2,200 planned
A first chapter book, with Zuri and Finn asking questions, clear diagrams and short explanations.
Fold 5 · Field Guide · Mine shaft
Rare StonesA Field Guide
- Ages
- 12+
- Trim
- 8 × 10 in
- Pages
- 48 planned
- Words
- 3,500–5,500 planned
A field guide for independent readers: compare minerals, follow the clues a gemologist uses and ask how scientists know.
Fold 6 · Deep Dive · Deep earth
Rare Stones, UnfoldedWhy Some Minerals Are So Hard to Find
- Ages
- 12+
- Trim
- 6 × 9 in
- Pages
- 64 planned
- Words
- 7,000–9,500 planned
Long-form popular science for teenagers and adults, with connected explanations, numbered notes and published sources.
Pilot edition, 2026. Printed on demand as premium-color paperbacks; ISBNs are assigned when the books are listed. See every fact they use