Use this recipe to make chocolate tarts with some culinary witchcraft.

We may have eaten delicious gems before, but we’ve never attempted to make them ourselves. But once we saw Japanese Twitter user @takahime117, show off their amazing-looking “Ruby and Sapphire Chocolate tarts,” we knew we had to try.

▼ Biting into solid rocks has never been so tempting.

@takahime117 went with red rubies and blue sapphires for their tarts (and so did we), but feel free to experiment with other colors if you’d like. By using other ingredients you could make green emeralds, white diamonds, and other precious gems to magically transport your desserts to a fantasy world. Here’s the recipe:


  • Water
  • Sugar
  • Food colouring
  • Agar powder (kanten), 5 grammes (0.18 ounces) – can usually be found in Asian supermarkets or natural food stores.
  • Chocolate tarts, cupcakes, or other pastries


1. Fill a small tupperware or plastic container with water, then add sugar until the water tastes sweet (and then add some more). Add the food colouring (red for rubies, blue for sapphires, etc.) until the liquid mixture has a deep, rich colour, as in the photo below, then add the five grammes of agar powder and caramelize the mixture.

2. Leave out to dry and harden. This will probably take two to four days. When it’s done, cut the now-solid mixture into crystal shapes, and the leftovers into smaller square or triangular chunks.

3. Prepare the chocolate tarts (or be lazy like us and buy some ready-made). You can use whatever pastries you’d like, but chocolate tarts look particularly good, as though the crystals are growing out of the ground.

4. Sprinkle powdered sugar onto the dessert and then position the crystals (or silver dragees, those little edible silver balls often found on cakes) as you like. Hopefully you have something that looks like this.

According to @takahime117, the important points to bear in mind are:

1. You should err on the side of extra sugar and really chuck it in when making the agar mixture to stop mould from forming as it dries.

2. The best combination seems to be one or two larger crystal shaped pieces, surrounded by several much smaller square and triangular pieces. Don’t overdo it with the crystals, or else it may end up looking messy.

▼ You can also put the crystals on chocolate cupcakes
if you want to go for more of a lava-crystal look.

Once prepared, you could then give these fantasy-esque goodies away as presents, use them for Halloween party snacks, or go ahead and make some edible jewels for dessert while you stuff your face with these for dinner. Not that we did that, of course….

Source, images: Twitter/@takahime117

[ Read in Japanese ]