In my latest video, I take a look at a powerful feature within Google Gemini that will be really useful for educators: Custom Gems.

If you find yourself repeatedly giving the same instructions to an AI – like “Act as a Year 4 teacher” or “Use the English National Curriculum” – then Gems are about to save you a massive amount of time. Think of a Gem as a “mini-AI” that you’ve pre-trained to be an expert in one specific area.

Watch the full tutorial here:

What Exactly is a Gem?

A Gem is a custom version of Gemini that stays “tuned” to your specific needs. Instead of starting a fresh chat every time, you can build a Gem that already knows your curriculum, your preferred tone of voice (less “AI-hype,” more “measured professional”), and your specific resource documents.

How to Build Your Custom Teaching Gem:

1. Head to the Gems Manager Open gemini.google.com and look for the Gems tab in the sidebar. You’ll see some pre-made options like “Brainstormer” or “Learning Coach,” which you can explore. But for this tutorial, click on New Gem.

2. Give it a Role and Instructions This is where you define the Gem’s personality. In the video, I use a framework covering:

  • Role: An expert in the English National Curriculum for Primary Science.
  • Objective: To provide accurate guidance and identify statutory vs. non-statutory objectives.
  • Style: Professional, concise, and – crucially for me – a “measured” British tone!
  • Pro Tip: If your initial prompt feels a bit messy, click the pencil icon and Gemini will rewrite it into a polished set of instructions for you.

3. Upload Your Knowledge Base This is the most powerful part. You can upload files (PDFs, Word docs, spreadsheets) directly into the Gem’s Knowledge section.

  • I uploaded the National Curriculum document for Science and a science knowledge matrix.
  • Now, whenever you ask a question, the Gem doesn’t just “guess” – it looks specifically at your documents to give you the answer.

4. Test and Refine On the right-hand side, you can test your Gem before saving. Try asking something like, “What are the Year 4 sound objectives and common misconceptions?” If the answer isn’t quite right, just tweak the instructions and try again.

5. Save and Share Once you’re happy, hit Save. Your Gem will now live in your sidebar for easy access. Even better? You can click Share to create a link for your colleagues, allowing your entire school or department to benefit from the same “expert” AI assistant.

Why Use Gems?

  • Consistency: It always remembers the rules you set.
  • Accuracy: It prioritizes the documents you’ve uploaded over general internet data.
  • Efficiency: No more copy-pasting the same prompts every morning.

The best part about Gems is that they grow with you. As your curriculum changes or you find new, high-quality resources, you can simply pop back into the settings and update your Gem’s “knowledge.” It’s like having a digital department head who never forgets a policy and is available 24/7 to help you plan your next big science unit. Give it a try, and let me know in the comments what kind of expert Gem you’re building for your classroom!