Is the Life Stone the only gem for my Lagna?

No. The Life Stone (ascendant lord) is the first recommendation. Other gems listed for that Lagna in the guide appear below it as optional benefics, sometimes with a 12th-lord caution.

How is gem weight calculated?

Minimum carats are body weight in kg divided by 12; the ideal is kg divided by 10. Ratti is carats divided by 0.91. Virgo Lagna Emerald may use a smaller high-clarity stone instead of chasing weight.

Vedic Gemstone Guide — Lagna and Weight

Gemstones amplify a planet; they do not cancel a malefic. Selection here is by Lagna (ascendant), not Moon rasi. The Life Stone is the Lagnadhipati gem (high priority). Other stones from the same traditional table are listed as benefics. Enter body weight to see minimum (kg/12) and ideal (kg/10) carats. Rahu and Ketu gems need a full chart and Dasha, not this form. Always confirm with a qualified astrologer before wearing a stone.

Gemstone Guide

Lagna

Body Weight (kg)

Notes on this guide

Wear day and finger were not listed in the source guide; weekdays and fingers shown here follow common practice and are labelled as such.
Mantras are mentioned in the source but not given here — do not invent them.
Rahu (Hessonite) and Ketu (Cat’s Eye) are not chosen from Lagna and weight; they need the full chart and Dasha.
The source table is planet → some lagnas, not a complete 1st/5th/9th-lord map (for example Leo 5th Jupiter / 9th Mars are omitted).
Pearl is the Moon’s primary gem; Moonstone is only a substitute.
Weight uses kg/12 (minimum) to kg/10 (ideal). The source chart sometimes lists a slightly higher “ideal”.
For Virgo, a high-clarity 3.5–5 carat Emerald can outweigh a larger cloudy stone.

Gemstone disclaimer