Once you know your size, choose your crystal. Each stone carries its own feel and intention — but there are practical differences too, and those matter more than most guides admit. Here is how nephrite jade, rose quartz, black obsidian and amethyst actually compare.

The hardness column is the Mohs scale, the standard mineralogical measure of scratch resistance. It is worth glancing at, because a stone that scratches easily develops a rougher surface over time, and surface is what you care about in an object like this.

Nephrite Jade — the traditional choice

Used this way for centuries: durable, grounding, forgiving. If you want one stone that simply works, start with jade.

Nephrite deserves its reputation on more than tradition. Mohs hardness only measures scratching; nephrite’s real advantage is toughness — its interlocking fibrous structure makes it remarkably resistant to chipping and cracking, which is exactly the property you want. It also takes and keeps a very smooth polish. For a first egg, and for anyone who wants something they will not have to fuss over, jade is the sensible answer.

Nephrite, jadeite and “new jade” — know what you are buying

This is the part worth reading carefully, because “jade” is one of the loosest words in the crystal trade. Two genuinely different minerals are sold as jade: nephrite and jadeite. Both are real jade. But a great deal of cheap green stone sold online is neither — it is dyed serpentine (often marketed as “new jade”), dyed quartz, or simply glass.

Three things help you tell the difference. Genuine nephrite feels cool to the touch and stays cool for a moment when you pick it up. It has a slightly waxy, greasy lustre rather than a glassy shine. And its colour has depth and variation — dyed material tends to look flat, or to show concentrated colour pooling in surface cracks. If a listing will not say nephrite outright, treat that as an answer. This is why we specify nephrite rather than just “jade”.

Rose Quartz — for self-love

The gentle pink stone of the heart, for a practice centered on self-compassion. Rose quartz is a variety of quartz, so at Mohs 7 it is genuinely hard and will not scratch easily — but hardness and toughness are not the same thing, and quartz is more brittle than nephrite. Dropped on a tiled floor it can chip where jade would survive. Handle it with a little care and check it over regularly.

Black Obsidian — for release

Volcanic glass, the stone of grounding and letting go. Keep it dry and cleanse it often. Because obsidian genuinely is a natural glass, it is the softest of the four here and the most likely to develop a chip — and a chipped glass edge can be sharp. That is not a reason to avoid obsidian, which is beautiful and much loved for this practice; it is a reason to run your fingers over the whole surface before each use and retire it the moment you feel anything but smooth.

Amethyst — for calm

Soft purple and calming, pairing your practice with mindfulness. Keep it out of long direct sun. Amethyst is quartz, so it shares rose quartz’s hardness and its brittleness, with one extra quirk: its colour genuinely does fade with prolonged sunlight exposure. Store it in its pouch rather than on a sunny windowsill and it will keep its depth for years.

Porosity, polish and why surface matters

Whichever stone you choose, the thing that actually matters day to day is the surface. You want a dense, non-porous, well-polished stone with no visible pits, cracks or crazing, because a smooth sealed surface is what makes an egg easy to keep clean. Stones with an open or grainy structure hold moisture and are a poor choice for this regardless of how pretty they look.

This is the practical argument behind the hygiene advice you will see everywhere: it is not really about the mineral, it is about whether the surface is intact. A flawless obsidian egg is easier to keep clean than a scratched piece of jade. Inspect, do not assume — and see our guide to cleaning and cleansing for the routine.

Which should you choose?

For the simplest, most durable start, choose jade. Otherwise choose by feeling — love (rose quartz), release (obsidian), or calm (amethyst). The best stone is the one you feel drawn to, and there is no hierarchy here; the intention you bring is the practice.

If you want the honest practical ranking rather than the intuitive one: nephrite jade first for durability, then rose quartz or amethyst, with obsidian requiring the most vigilance. New to it all? Begin with the jade set of three sizes, and read which size to start with before your first session.

Common questions

Is nephrite or jadeite better for a yoni egg?

Nephrite, for toughness. Jadeite is the rarer and more valuable jade in jewellery terms, but nephrite’s fibrous structure resists chipping better, which is what counts here.

How can I tell if my jade egg is real?

Genuine nephrite feels cool, has a waxy rather than glassy lustre, and shows natural colour variation. Dye tends to pool in surface cracks and looks flat. If the seller will not use the word nephrite, be sceptical.

Is black obsidian safe to use?

Yes, provided the surface is perfectly smooth and undamaged. It is a natural glass, so it is the most chip-prone of the common stones — check it before every use and retire it if you find any chip or rough patch.

Can I own more than one stone and swap between them?

Certainly, and many people do — a different stone for a different intention. Just keep each one clean and stored separately so they do not knock against each other.

Does the crystal type change how effective the exercise is?

No. The pelvic-floor work is identical whichever stone you hold; the stone is about feel, durability and the intention you bring to the practice.

A yoni egg is a wellness and pelvic-floor (Kegel) exercise tool, not a medical device. If you are pregnant, have an IUD, an infection, or any concern, please check with your healthcare provider first, and always listen to your body.