Igneous (from magma)
Crystals grow as molten rock cools. Peridot comes up in basalt from the upper mantle. Diamond forms 150–200 km down and is carried up in kimberlite eruptions. Moonstone and sunstone grow in volcanic and plutonic rocks.
A mineral is a naturally occurring, inorganic solid with a definite chemical composition and an ordered internal structure. When those atoms repeat in a regular 3‑D lattice, the solid is a crystal, and the lattice is why crystals grow flat faces and sharp angles. A rock is a mixture of minerals (granite is quartz + feldspar + mica). A gem is any material cut or polished for adornment because it is beautiful, durable and rare.
Not every gem is a crystalline mineral:
About 6,000 mineral species are known. Roughly 300 are cut as gems, and only a few dozen are traded in meaningful quantity. This encyclopedia covers those, plus the stones popular in crystal shops and in Indian astrology.
Every crystal belongs to one of seven systems based on the symmetry of its unit cell. The system controls the crystal's shape and many optical properties.
| System | Axes | Typical shape | Examples |
|---|---|---|---|
| Cubic (isometric) | 3 equal, all at 90° | Cubes, octahedra | Diamond, garnet, spinel, pyrite, fluorite |
| Tetragonal | 2 equal + 1 different, 90° | Square prisms | Zircon, rutile, apophyllite |
| Hexagonal | 3 equal at 120° + 1 perpendicular | Six‑sided prisms | Beryl (emerald, aquamarine), apatite |
| Trigonal | Like hexagonal, 3‑fold symmetry | Three/six‑sided prisms, rhombohedra | Quartz, corundum (ruby, sapphire), tourmaline, calcite |
| Orthorhombic | 3 unequal, all 90° | Rectangular prisms | Topaz, peridot, chrysoberyl, tanzanite |
| Monoclinic | 3 unequal, one angle ≠ 90° | Tilted prisms | Jadeite, kunzite, moonstone, malachite |
| Triclinic | 3 unequal, no right angles | Flattened, asymmetric | Labradorite, turquoise, kyanite, amazonite |
| Amorphous | No lattice | Rounded, conchoidal | Opal, obsidian, amber, moldavite |
Crystals grow when atoms in a liquid, gas or hot solid have the time, space and chemistry to lock into a lattice. Slow cooling and open space give large, clean crystals. Fast cooling gives tiny crystals or glass. Most gems need an unusual ingredient, such as beryllium, boron, chromium or lithium, concentrated in the right place. That's why they are rare.
Crystals grow as molten rock cools. Peridot comes up in basalt from the upper mantle. Diamond forms 150–200 km down and is carried up in kimberlite eruptions. Moonstone and sunstone grow in volcanic and plutonic rocks.
These are the last, water‑rich pockets of a cooling granite magma, enriched in rare elements. Crystals here can grow huge. Pegmatites are the home of aquamarine, morganite, tourmaline, topaz, kunzite and spessartine garnet.
Hot mineral‑rich water moves through cracks and deposits crystals as it cools. This produces quartz points and clusters, amethyst geodes, Colombian emeralds, fluorite, rhodochrosite and agate bands.
Existing rocks recrystallise under heat and pressure without melting. Marble hosts Burmese rubies and spinel. Schist hosts many garnets, kyanite and some emeralds. Tanzanite and jade also form this way.
Minerals precipitate as water evaporates or percolates through sediment. Examples are selenite (gypsum), celestite, desert rose and opal (silica gel in cavities). Weathering also concentrates gems into river gravels, called placer deposits, which is how most Sri Lankan sapphires are mined.
Near the surface, groundwater alters copper ore into colorful secondary minerals: malachite, azurite, chrysocolla, turquoise and dioptase.
Molluscs secrete nacre (aragonite + conchiolin) around an irritant to make pearls. Coral polyps build calcium‑carbonate skeletons. Tree resin hardens over millions of years into amber.
Lava that cools too fast to crystallise becomes obsidian. A meteorite impact about 15 million years ago melted rock into moldavite. Libyan desert glass and other tektites formed similarly.
Factories reproduce these conditions using flame fusion, flux, hydrothermal growth or HPHT/CVD for diamond. Synthetic stones are chemically identical to natural ones. Imitations, by contrast, are different materials that only look similar, such as glass or cubic zirconia.
Jyotish (Vedic astrology) links each of the nine grahas (planets) to a gem. Classical sources on gem lore and testing include the Garuda Purana (Ratna Pariksha), the Brihat Samhita of Varahamihira, the Agni Purana, and later texts such as the Mani Mala. The idea is that a gem strengthens the planet whose light it carries. Practitioners therefore recommend gems for planets that are favourable in your chart but weak. They do not recommend gems to "fix" a harmful planet, because that would amplify it.
| Graha | Navaratna | Common Uparatna (substitutes) | Metal | Finger | Day |
|---|---|---|---|---|---|
| Sun (Surya) | Ruby (Manik) | Red spinel, sunstone (some use red garnet) | Gold, copper | Ring | Sunday |
| Moon (Chandra) | Pearl (Moti) | Moonstone | Silver | Little / ring | Monday |
| Mars (Mangal) | Red coral (Moonga) | Carnelian | Gold, copper | Ring | Tuesday |
| Mercury (Budh) | Emerald (Panna) | Peridot, green tourmaline, green onyx, jade | Gold | Little | Wednesday |
| Jupiter (Guru) | Yellow sapphire (Pukhraj) | Citrine, yellow topaz | Gold | Index | Thursday |
| Venus (Shukra) | Diamond (Heera) | White sapphire, white zircon, opal | Silver, platinum, white gold | Middle / ring | Friday |
| Saturn (Shani) | Blue sapphire (Neelam) | Amethyst, iolite, lapis lazuli | Silver, panchdhatu | Middle | Saturday |
| Rahu | Hessonite (Gomed) | Red garnet, orange zircon, spessartine | Silver, panchdhatu | Middle | Saturday |
| Ketu | Cat's eye (Lehsunia) | Tiger's eye, cat's‑eye apatite | Silver, panchdhatu | Middle | Tuesday (some say Thursday) |
The finger and day vary between schools. The detail page for each stone records the most common practice and notes where traditions differ.
| Lagna | Life stone (lagna lord) | Also favourable | Usually avoided |
|---|---|---|---|
| Aries (Mesha) | Red coral | Ruby, yellow sapphire | Emerald, diamond |
| Taurus (Vrishabha) | Diamond | Blue sapphire, emerald | Ruby, red coral, yellow sapphire |
| Gemini (Mithuna) | Emerald | Diamond, blue sapphire | Red coral, pearl |
| Cancer (Karka) | Pearl | Red coral, yellow sapphire | Emerald, diamond, blue sapphire |
| Leo (Simha) | Ruby | Red coral, yellow sapphire | Diamond, blue sapphire |
| Virgo (Kanya) | Emerald | Diamond, blue sapphire | Red coral, pearl |
| Libra (Tula) | Diamond | Blue sapphire, emerald | Ruby, yellow sapphire |
| Scorpio (Vrischika) | Red coral | Yellow sapphire, pearl, ruby | Emerald, diamond |
| Sagittarius (Dhanu) | Yellow sapphire | Ruby, red coral | Diamond, blue sapphire |
| Capricorn (Makara) | Blue sapphire | Diamond, emerald | Ruby, pearl, red coral |
| Aquarius (Kumbha) | Blue sapphire | Diamond, emerald | Ruby, red coral, pearl |
| Pisces (Meena) | Yellow sapphire | Red coral, pearl | Diamond, emerald, blue sapphire |
This is a general guideline from common Parashari practice. Astrologers make the final choice from the full chart, looking at planetary strength, house placement and dasha.
| Planet | Friends | Neutral | Enemies |
|---|---|---|---|
| Sun | Moon, Mars, Jupiter | Mercury | Venus, Saturn |
| Moon | Sun, Mercury | Mars, Jupiter, Venus, Saturn | None |
| Mars | Sun, Moon, Jupiter | Venus, Saturn | Mercury |
| Mercury | Sun, Venus | Mars, Jupiter, Saturn | Moon |
| Jupiter | Sun, Moon, Mars | Saturn | Mercury, Venus |
| Venus | Mercury, Saturn | Mars, Jupiter | Sun, Moon |
| Saturn | Mercury, Venus | Jupiter | Sun, Moon, Mars |
Rahu is generally treated like Saturn and Ketu like Mars when combining gems.
A Navaratna ring or pendant carries all nine gems in a fixed arrangement. Ruby sits in the centre, ringed by diamond (east), pearl (south‑east), red coral (south), hessonite (south‑west), blue sapphire (west), cat's eye (north‑west), yellow sapphire (north) and emerald (north‑east). Because all nine planets are balanced, it is traditionally considered safe for anyone to wear.
Crystal healing and Vedic astrology follow different logic, so a good combination depends on which tradition you follow. Physical compatibility matters either way.
In jyotish, gems of planets that are natural enemies are not worn together. Each would strengthen a planet that opposes the other. The most commonly cited pairs to avoid:
| Don't combine | With | Why |
|---|---|---|
| Ruby (Sun) | Blue sapphire, diamond, hessonite | Saturn and Venus are the Sun's enemies; Rahu acts like Saturn |
| Pearl (Moon) | Hessonite, cat's eye; often blue sapphire and diamond too | Rahu and Ketu eclipse the Moon; Saturn and Venus treat the Moon as an enemy |
| Red coral (Mars) | Emerald, blue sapphire, hessonite | Mars treats Mercury as an enemy; Saturn treats Mars as one |
| Emerald (Mercury) | Pearl, red coral | Mercury treats the Moon as an enemy |
| Yellow sapphire (Jupiter) | Diamond, emerald, blue sapphire (by many) | Jupiter treats Venus and Mercury as enemies |
| Diamond (Venus) | Ruby, pearl, yellow sapphire | Venus treats the Sun and Moon as enemies |
| Blue sapphire (Saturn) | Ruby, pearl, red coral | Saturn treats the Sun, Moon and Mars as enemies |
The same rule applies to their substitutes. Amethyst (Saturn) and sunstone (Sun) shouldn't be mixed, for example. A full set of all nine planets, as in a Navaratna or Navagraha bracelet, is the traditional exception: it is considered balanced. Rudraksha is believed to be compatible with any gem.
The bracelet designer has a "Sacred count" setting that sets one of these counts and suggests the bead size that fits your wrist.
The combinations page applies these rules automatically to each combination. You can check your own design in the combo checker.
The geology and gemology here are established science. The metaphysical and Vedic sections describe cultural and religious traditions. There's no scientific evidence that stones or rudraksha change health, luck or behaviour. Treat those sections as an account of belief and practice, not as medical or financial advice. For astrological recommendations, consult a qualified jyotishi with your full birth chart.
What it is: Rudraksha is the dried stone (endocarp) of the fruit of Elaeocarpus ganitrus (also called E. angustifolius). It is a large, fast-growing evergreen tree (up to about 18–24 m) found from the Himalayan foothills of India and Nepal through Southeast Asia and Indonesia (Java, Bali, Sumatra) to New Guinea and northern Australia. Its accepted botanical name varies between databases: many treat E. ganitrus as a synonym of E. angustifolius, while Kew's Plants of the World Online places it under E. sphaericus. Seeds of a few other Elaeocarpus species are also sold as rudraksha. The ripe fruit is a striking blue. That colour is structural: it comes from microscopic reflective layers in the skin, not from pigment (Lee, Nature, 1991). When the pulp is removed, the hard, grooved seed inside is the bead.
Mukhi (faces): The natural clefts running from pole to pole are called mukhis. Each mukhi matches a seed chamber (locule) inside, which is why an X‑ray is the reliable authenticity test. Most beads are 5‑mukhi. The classical texts list 1 to 14 mukhi; the trade recognises 1 to 21, anything above 14 is very rare, and beads with up to 26–27 faces have been reported.
Origins: Nepali beads are large (roughly 15–35 mm), with deep, clear mukhis. They are prized and expensive. Indonesian (Java) beads are mostly small (about 5–15 mm, though higher mukhis can reach about 25 mm), smoother and more affordable, and are favoured for malas. Indian beads come from several regions, including the north‑east and the Himalayan foothills; the half‑moon 1‑mukhi is traded as a South Indian bead.
Meaning: The name joins Rudra (Shiva) and aksha (eye, or tears). The Shiva Purana (Vidyeshvara Samhita, ch. 25) says the trees grew from tears that fell from Shiva's eyes after a thousand divine years of penance, and gives a deity and mantra for each bead from 1 to 14 mukhi. The Devi Bhagavata Purana (Book 11) and the Rudrakshajabala Upanishad tie the tears to Shiva's long vigil before destroying the demon Tripura. Rudraksha is not a planetary gem in classical Jyotish. Its link to planets is a later tradition, but it is widely worn alongside or instead of gems because it is believed to have no harmful side effects.
| Nepal | Indonesia (Java) | India | |
|---|---|---|---|
| Size | Large, about 15–35 mm | Mostly small, about 5–15 mm (up to ~25 mm) | Varies; half‑moon 1‑mukhi traded from the south |
| Mukhi lines | Deep and clear | Shallow, finer | Varies |
| Best for | Single pendants, higher mukhis | Japa malas and bracelets | Regional use |
| Price | Higher | Lower | Varies |
The Shiva Purana does grade size (a bead the size of an amla fruit is best, jujube size middling, gram size lowest), but in modern practice size isn't thought to change the meaning of a mukhi. Choose by budget, comfort and how clearly the mukhis can be counted.
| Mala | Beads | Used for |
|---|---|---|
| Japa mala | 108 beads + 1 guru (sumeru, meru or bindu) bead, usually 5‑mukhi; Java malas are often 5–8 mm, Nepali malas larger | Counting mantra repetitions. The guru bead marks the start and is not crossed; at the end you turn the mala and go back. |
| Half and quarter malas | 54+1 or 27+1 beads | Shorter japa, or worn on the wrist. |
| Kantha (neck) mala | Fewer, larger beads, often Nepali | Worn rather than used for counting. |
| Indrakshi mala | Varies by dealer: the largest dealers use one each of 1 to 21 mukhi plus Gauri Shankar, Garbh Gauri, Ganesh, Trijuti and Sawar; simpler versions use 1 to 14 mukhi plus Gauri Shankar | Regarded in the trade as the most complete rudraksha combination; very expensive. |
| Siddha mala | Usually 1 (or 2) to 14 mukhi plus Gauri Shankar and Ganesh, padded to 108+1 with 5‑mukhi in some versions; the exact make‑up varies by maker | A broad combination for overall wellbeing in popular practice; overlaps with Indrakshi. |
| Navagraha set | 1 to 9 mukhi, one for each planet | Balancing the nine grahas in modern practice; which mukhi goes with which planet varies by seller. |
| Rudraksha–sphatik mala | Alternating rudraksha and clear quartz | A popular combination for meditation and japa. |
| Bracelet | About 21–27 Java beads, or 7–9 Nepali beads, often capped in silver | Everyday wear. |
Why 108? Explanations differ: 12 rashis × 9 grahas, or 27 nakshatras × 4 padas, among others; these are later interpretations rather than a single agreed reason. The Devi Bhagavata already prescribes 108 beads for a japa mala, and 108 is a sacred number in Hindu, Buddhist and Jain practice.
The Shiva Purana gives bead counts for wearing rudraksha on different parts of the body. Translations differ in the exact numbers:
| Where | Shiva Purana (Debroy translation) | Other translations |
|---|---|---|
| Each wrist | 12 | 11 |
| Each arm | 16 | 11 (with 11 at each elbow) |
| Neck | 50, or 32 in a second list | 101 |
| Head | 30–40 | |
| Each ear | 6 | 6 |
| Chest (mala) | 108 | |
| Top-knot (shikha) | 1 | 3 |
For japa, the Devi Bhagavata prescribes a mala of 108 beads; the smaller malas are fractions of it (54, 36, 27), and wrist malas commonly have 18–27 beads. A single bead worn as a pendant is also traditional, especially for rare mukhis. These counts are matters of tradition; texts describe the merit of wearing more beads, but no count is needed for a bead to be "active".
Sources: Shiva Purana (Vidyeshvara Samhita) in Bibek Debroy's translation and other translations; Devi Bhagavata Purana, Book 11. Set any of these counts in the bracelet designer.
Practice varies by family and teacher. A common sequence is:
Traditional restrictions: some traditions ask that rudraksha be removed when bathing with soap, while sleeping, at funerals and cremation grounds, and during intimacy, and that a personal japa mala not be shared. The Shiva Purana also tells wearers to avoid meat, onion, garlic and alcohol. Many modern teachers treat these as optional. Follow the guidance of your own tradition.
See Real or fake rudraksha for side‑by‑side comparisons.