Geng Metal (庚) and Xin Metal (辛) share the Metal element but express it in opposite modes: Geng is Yang Metal — the unforged sword that cuts through obstacles by raw force and blunt honesty — while Xin is Yin Metal — the polished jewel that achieves through precision, refinement, and strategic positioning. Because the Ten Gods are calculated relative to your specific Day Stem, mistaking one for the other inverts the chart’s career, wealth, and relationship readings entirely.
In the Four Pillars system (BaZi / Korean Saju, 사주), the Day Master (日主) is the Heavenly Stem of your Day Pillar — the single most important indicator of your core nature. Two people can both be Metal Day Masters yet have fundamentally different favorable elements, career patterns, and relationship stars, because one is Yang Metal and the other is Yin Metal.
This is not a matter of degree. The Ten Gods — the ten relational stars that govern wealth, career, output, seals, and companions — are calculated by comparing your Day Stem to every other stem in the chart. Because Yang and Yin of the same element invert the polarity relationship, every single Ten God assignment flips between Geng Metal and Xin Metal. Ren Water (壬) is Geng’s Eating God and Xin’s Hurting Officer. Bing Fire (亮) is Geng’s Seven Killings and Xin’s Direct Officer. Getting the Day Master right is not optional — it is the prerequisite for every subsequent analysis.
Geng is the 7th Heavenly Stem and the Yang expression of Metal. Classical texts characterize it with the phrase 御金带梲，划健为最 — roughly, “Geng Metal carries the killing quality; it is the firmest of all.” The images are a forged sword, a great axe, raw iron ore, or a large boulder: unfinished power that does not need to be refined because its raw edge is precisely its strength.
The classical formula for Geng Metal is 御金巧然，金溶乖其瞟，水海沙其涘 — “When Geng Metal is firmly established, Fire refines its edge and Water washes it clear.” In practical Ten God terms:
A strong Geng Metal chart generally benefits most from Fire (to shape it) and Water (to purify and express). A weak Geng chart first needs Earth support before Fire can be used. Season of birth matters: autumn-born Geng Metal (Metal season) is already strong and needs less Earth.
Geng Metal’s natural mode — direct force, structural authority, decisive confrontation — maps best onto roles where these qualities are advantages rather than liabilities: law (litigation, prosecution), surgery, military and security leadership, structural engineering, crisis management, investment banking where conviction matters, and executive roles requiring hard decisions. In any field, Geng Metal operates best with clear authority and clear opponents.
Xin is the 8th Heavenly Stem and the Yin expression of Metal. Classical texts describe it as 辛金软弱，溢炬而清 — “Xin Metal is gentle and soft, warm and luminous.” The images are a cut gem, fine jewelry, a slender needle, or polished gold: metal that has already been refined, whose value lies in precision and luster rather than raw force. Do not mistake the soft description for weakness — it is still metal, and its core is unyielding.
The most celebrated classical principle for Xin Metal is 壬水洗辛 — “Ren Water washes Xin Metal.” Like water over a gemstone, Ren Water activates Xin Metal’s innate luminosity. In Ten God terms, however, Ren Water (壬) is Xin’s Hurting Officer (伤官) — a star of brilliant, unconventional talent that can conflict with institutional authority if unchecked. The principle holds: Ren Water genuinely polishes Xin, but excess without Fire or Wood balance creates instability.
Xin Metal fears two things above all: strong Ding Fire (丁 = Seven Killings for Xin) without Water to control it — which melts the jewel — and excess Earth burying it without Water to wash it clear. Both scenarios suppress the luminosity that is Xin Metal’s defining quality.
Xin Metal excels wherever refinement, precision, and indirect influence create more value than brute force: jewelry design, luxury fashion, beauty and aesthetics, diplomacy, high-level negotiation and mediation, strategic consulting, writing and editorial work, curatorship, and roles in healthcare or science requiring fine-motor precision. In business, Xin Metal often functions best as the advisor, strategist, or specialist rather than the commanding executive — though when a Xin chart carries a strong Direct Officer structure, formal leadership roles can be highly successful.
| Dimension | Geng Metal (御) | Xin Metal (辛) |
|---|---|---|
| Polarity | Yang (陳) | Yin (阴) |
| Classical symbol | Sword, axe, raw ore | Jewel, fine needle, refined gold |
| Core approach | Direct force | Strategic precision |
| Ren Water (壬) Ten God | Eating God 饼神 | Hurting Officer 伤官 |
| Gui Water (畋) Ten God | Hurting Officer 伤官 | Eating God 饼神 |
| Bing Fire (亮) Ten God | Seven Killings 七梲 | Direct Officer 正官 |
| Ding Fire (丁) Ten God | Direct Officer 正官 | Seven Killings 七梲 |
| Male spouse star | Yi Wood (乙) — Direct Wealth | Jia Wood (甲) — Direct Wealth |
| Female spouse star | Ding Fire (丁) — Direct Officer | Bing Fire (亮) — Direct Officer |
| Primary strength | Decisiveness, integrity, loyalty | Precision, strategy, refinement |
| Primary challenge | Inflexibility, bluntness | Over-sensitivity, avoidance |
| Best career mode | Commands authority directly | Advises, refines, positions |
| Key favorable element | Ding Fire (refines) + Ren Water (expresses) | Ren/Gui Water (polishes) + Bing Fire (illuminates) |
This table is the analytical foundation. Every career, wealth, output, and relationship star flips between the two Day Masters because Yang and Yin invert all polarity relationships.
| Heavenly Stem | Geng Metal (御) Ten God | Xin Metal (辛) Ten God |
|---|---|---|
| 甲 Jia Wood | Indirect Wealth 偏財 | Direct Wealth 正財 |
| 乙 Yi Wood | Direct Wealth 正財 | Indirect Wealth 偏財 |
| 亮 Bing Fire | Seven Killings 七梲 | Direct Officer 正官 |
| 丁 Ding Fire | Direct Officer 正官 | Seven Killings 七梲 |
| 斎 Wu Earth | Indirect Seal 偏印 | Direct Seal 正印 |
| 己 Ji Earth | Direct Seal 正印 | Indirect Seal 偏印 |
| 御 Geng Metal | Parallel 比胃 | Rob Wealth 劫財 |
| 辛 Xin Metal | Rob Wealth 劫財 | Parallel 比胃 |
| 壬 Ren Water | Eating God 饼神 | Hurting Officer 伤官 |
| 畋 Gui Water | Hurting Officer 伤官 | Eating God 饼神 |
Because the wealth stars (財 stars, which govern romantic partners for men) and officer stars (官 stars, which govern partners for women) are drawn from different stems, the two Metal Day Masters have distinct relationship archetypes.
Geng Metal men carry Yi Wood (乙) as Direct Wealth (正財) — their primary spouse indicator. Yi Wood is Yin Wood: the flexible vine, the graceful willow. There is an archetypal complement here: the unyielding sword finds its partner in something adaptable and yielding. Geng Metal men are drawn to partners who offer warmth, adaptability, and emotional intelligence as counterbalance to their own directness.
Geng Metal women carry Ding Fire (丁) as Direct Officer (正官) — the refining flame that shapes the sword. They are drawn to principled, steady, and purposeful partners — someone who provides direction without being oppressive. Bing Fire (亮), by contrast, is Seven Killings for Geng women: an intensely charged, potentially transformative but destabilising partner dynamic.
Xin Metal men carry Jia Wood (甲) as Direct Wealth (正財) — strong, upright Yang Wood, the tall tree. The refined jewel pairs with grounded, steadfast strength. Xin Metal men tend to value partners who provide stable foundation and decisive presence as counterweight to their own refinement.
Xin Metal women carry Bing Fire (亮) as Direct Officer (正官) — the broad sunlight that illuminates the gem and makes it brilliant. This is the same Bing Fire that creates conflict for Geng women. For Xin Metal women, a Bing Fire year or Luck Pillar is often a period of relationship activation and career visibility simultaneously — because the same star governs both.
In Korean Saju (사주), the same Four Pillars framework applies without modification. Geng Metal is romanised as Gyeong (경) and Xin Metal as Sin (신). The Heavenly Stem cycle, Ten God system, and favorable-element logic are identical to classical BaZi. If your Korean Saju chart shows 경 as the Day Stem, everything in the Geng Metal sections above applies directly to your reading.
Your Day Master is determined by the Heavenly Stem of your Day Pillar, not your year or month. The ten Heavenly Stems cycle on a ten-day rotation indefinitely. To find yours:
The Hour of birth shifts the Day Pillar assignment for births near midnight. If you were born between 23:00 and 00:59, verify with an accurate calculator that accounts for the hour boundary.
Geng Metal (御) is Yang Metal — characterized in Di Tian Sui (滞天隈) as carrying the killing quality and being the firmest of all elements. It operates through direct force, blunt honesty, and decisive confrontation. Xin Metal (辛) is Yin Metal — described as gentle and luminous, delighting in Water and fearing excess Earth. It operates through precision, indirect influence, and strategic positioning. Both are Metal, but Geng is the unforged sword while Xin is the polished jewel — and their Ten God assignments are systematically opposite for every Heavenly Stem in the chart.
Enter your exact solar birth date into a BaZi or Korean Saju calculator. The Day Master is the Heavenly Stem (upper character) of the Day Pillar column — not the Year Pillar. If the stem reads 御 (Geng), you are Geng Metal; if it reads 辛 (Xin), you are Xin Metal. The ten stems cycle every ten days, so the same Day Stem recurs on a ten-day rotation. If you were born between 23:00 and 00:59, verify the hour boundary, as the solar day transition can shift the Day Pillar assignment.
Ten Gods are assigned by comparing the polarity and elemental relationship between your Day Stem and every other stem. Metal produces Water in the productive cycle, so both Day Masters “produce” Water. But Ren Water (壬) is Yang — the same polarity as Geng Metal (Yang), making it Geng’s Eating God (饼神): a star of creative output, comfortable talent expression, and wealth through skill. Ren Water is opposite polarity to Xin Metal (Yin), making it Xin’s Hurting Officer (伤官): brilliant unconventional talent that can strain authority relationships. Xin’s Eating God is Gui Water (畋) instead. This single swap reverses the chart interpretation for output stars and favorable Water elements entirely.
Yes. For Geng Metal males, the Direct Wealth star (正財, primary partner indicator) is Yi Wood (乙). For Xin Metal males, it is Jia Wood (甲). For Geng Metal females, the Direct Officer star (正官, primary partner indicator) is Ding Fire (丁). For Xin Metal females, it is Bing Fire (亮). The critical implication: because Bing Fire is Seven Killings (七梲) for Geng Metal females and Direct Officer (正官) for Xin Metal females, a chart or Luck Pillar dominated by Bing Fire reads as power struggle and destabilisation for Geng women, and as career and relationship activation for Xin women — a directly opposite reading of the same element.
Geng Metal thrives in roles where direct force, structural authority, and decisive confrontation are advantages: litigation and prosecution, surgery, military and security leadership, structural and mechanical engineering, crisis management, investment banking, and executive roles requiring hard decisions under pressure. Xin Metal excels where refinement, precision, and indirect influence create the highest value: jewelry and luxury design, fashion and beauty, diplomacy and mediation, high-level strategic consulting, writing and editorial work, and roles in aesthetics or specialist medicine requiring fine precision. Both types can succeed in finance and law, but Geng Metal commands while Xin Metal advises — and the execution difference matters significantly even when the title is the same.
Chart accuracy depends on your exact solar birth date and hour. The Hour Pillar affects Day Master assignment for births near midnight.