# What are Gems in Gemini?

> Gems are custom versions of Google's Gemini set up for one job with instructions and reference files. How to build one, modeled on an ad copy writer.

Source: https://learn.ynteractive.com/content/glossary/gemini-gems · Updated 2026-10-01 · Free from Stepthrough (https://learn.ynteractive.com)

[AI assistants](https://learn.ynteractive.com/content/glossary#topic-ai-assistants) · [AI glossary](https://learn.ynteractive.com/content/glossary)

Updated October 1, 2026 · By [Robert Breen](https://learn.ynteractive.com/content/about)

Gems are custom versions of Google's Gemini assistant that you set up for one job, with a name, standing instructions and, optionally, files to use as reference. You open the Gem whenever you need that job done instead of re-explaining it.

## Why it matters for a small business

The instinct that makes a Custom GPT useful applies to Gems: repeated tasks deserve fixed rules. A Gem for ad copy, another for customer replies and another for job posts means each follows its own format and limits without anyone pasting a page of setup first.

For Google Workspace businesses, Gems also keep the work near the materials, since reference documents often already live in Drive. As with any assistant, a Gem's output is a draft. Rules reduce mistakes; they don't remove the need to read before you publish.

## In a real lesson: Build a Custom GPT Ad Copy Writer for Search and Social Ads

Stepthrough's lessons build Custom GPTs in ChatGPT, not Gems, but the setup is the same idea. In the [ad copy GPT lesson](https://learn.ynteractive.com/content/custom-gpt-ad-copy-writer) you build **Ad Copy Writer** for Harbor & Pine Coffee Roasters, a made-up small online coffee brand.

Its instructions would suit any Gem because they are so specific: Google search headlines of 30 characters max (write 3), descriptions of 90 characters max (write 2), Facebook and Instagram primary text of 125 characters and headlines of 40, a character count after every line, no health claims, no fake urgency, and only offers from the brand guide. The reference file is **Harbor-Pine-Brand-Voice.pdf**, with tone rules, current products and offers, and sample ads.

To rebuild it as a Gem, you'd paste the same instructions into the Gem, add the brand guide as a reference file, and test with the lesson's request: **Write ad copy for my coffee company's new holiday blend**. Then count characters yourself on a few lines, because AI counts aren't always exact.

[Try this lesson free](https://learn.ynteractive.com/modules/chatgpt-custom-gpt-marketing) or [read the step-by-step guide](https://learn.ynteractive.com/content/custom-gpt-ad-copy-writer).

## Common confusions

### Gems vs Custom GPTs

Same concept on different platforms: Google's Gemini versus OpenAI's ChatGPT. Both combine instructions with optional reference files. Use whichever your business already uses and has approved; see [Custom GPT](https://learn.ynteractive.com/content/glossary/custom-gpt).

### Gems vs NotebookLM

A Gem is an assistant with a job and a style. [NotebookLM](https://learn.ynteractive.com/content/glossary/notebooklm) is for asking questions of a set of source documents, with answers that point back to those sources.

## Tips

- Start from instructions that already work in another assistant; they usually transfer with little change.
- Name each Gem after its job so the team picks the right one.
- Re-test whenever you change the reference file or the instructions.

## Related terms

[Gemini](https://learn.ynteractive.com/content/glossary/gemini) · [Custom GPT](https://learn.ynteractive.com/content/glossary/custom-gpt) · [GPT instructions](https://learn.ynteractive.com/content/glossary/gpt-instructions) · [Knowledge files](https://learn.ynteractive.com/content/glossary/gpt-knowledge-files) · [Ad copy](https://learn.ynteractive.com/content/glossary/ad-copy) · [Brand voice](https://learn.ynteractive.com/content/glossary/brand-voice)

## Where to learn more

[AI for Marketing](https://learn.ynteractive.com/content/industry/marketing) · [ChatGPT tutorials](https://learn.ynteractive.com/content/tool/chatgpt)

## Frequently asked questions

**Can I share a Gem with my team?**

Sharing options depend on your Google account and current features. If sharing isn't available to you, keep the Gem's instructions in a shared doc so others can create the same Gem.

**Does a Gem get better on its own over time?**

No. It follows the instructions and files you set. To improve it, edit the instructions when you see a rule being missed, then test again.

[All AI glossary terms, A to Z](https://learn.ynteractive.com/content/glossary) · [Free prompt templates](https://learn.ynteractive.com/content/prompts)