Skip to content
Corundum Foundation at a glance

· Private foundation

Corundum Foundation

Its FY2025 filing reports that it funds preselected organizations and did not take unsolicited requests; check the foundation's own site before ruling it out.

$24k
Granted FY2025still arriving
4
Grants FY2025still arriving
2
States reached
$10k
Largest
01What it fundsRead
02The needRead
03Its granteesRead
04Its fieldRead
05Through PlinthRead
01What it funds
01100% classified

What it funded, over time

Every grant placed by its stated purpose and the recipient’s mission, by year, FY2017 to 2024.

Education$283kAnimals$250kHealth$92kReligion$30kEmployment$11kEnvironment$10kInternational$3kArts & Culture$2kOther$0
02FY2025 · 4 grants

Where the money goes

Grants by size, and the largest recipients.

By grant size · FY2025

  • Under $10k2 grants · $4k
  • $10k–50k2 grants · $20k
$10,000
Median grant
2
States reached
$14k
Total assets
Largest grants
RecipientAmount
CHILDREN'S HOSPITAL COLORADO$10,000
STARABILITY FOUNDATION$10,000
ST PAUL CATHOLIC CHURCH$2,500
UNIVERSITY OF COLORADO$1,000
02The need
03

Does the money reach high-need areas?

Each grant placed by the hardship in its grantee’s ZIP, against the area’s typical level.

show:

Dollar for dollar, its grants (FY17–25) land where the poverty rate runs at 9%, against an area that typically sits at 8%. 99% of its dollars go to grantees based in above-average-need neighborhoods. Most of its grants land in higher-need ZIPs.

area typical 8%Gustavas Adolphus College: $125k → 9%Scottish Rite Foundation of Duluth: $50k → 15%Explore Ecology: $10k → 14%Kealakehe High School: $3k → 15%STARability Foundation: $10k → 10%St Paul Catholic Church: $5k → 5%Children's Hospital Colorado: $10k → 9%UNIVERSITY OF COLORADO: $1k → 12%National Alliance on Mental Illness: $1k → 7%Fostering Hope: $1k → 9%Gustavus Adolphus College: $60k → 9%STARABILITY FOUNDATION: $10k → 10%CHILDREN'S HOSPITAL COLORADO: $10k → 9%National Alliance on Mental Illness: $1k → 7%Gustavus Adolphus College: $35k → 9%First United Methodist Church: $10k → 9%Gustavas Adolphus College: $25k → 9%Children's Hospital Colorado Foundation: $10k → 9%Gustavas Adolphus College: $25k → 9%Children's Hospital of Colorado: $10k → 9%Gustavas Adolphus College: $10k → 9%Discover Goodwill: $10k → 9%Discover Goodwill of Southern and Western Colorado: $1k → 9%UCCS: $5k → 9%Air Academy High School Band: $500 → 9%Cheyenne Mountain Zoo: $100k → 9%Cheyenne Mountain Zoo: $50k → 9%Cheyenne Mountain Zoo: $50k → 9%Cheyenne Mountain Zoo: $25k → 9%Cheyenne Mountain Zoo: $25k → 9%St Paul Catholic Church: $5k → 9%St Paul Catholic Church: $5k → 9%ST PAUL CATHOLIC CHURCH: $3k → 9%Colorado Springs Fine Arts Center: $2k → 9%Care and Share Food Bank: $1k → 9%0%20%40%50%more need →
grant to an above-average-need area below average· circle size = grant amount
How this is measured
Matched: human-services grants are those whose grantee’s IRS cause code is Human Services. Placed by people below the poverty line in the grantee’s ZIP, averaged from the tracts in that ZIP.

Which US states its grants reach

MN
CA
CO
MO
VA
DC
HI
FL
How this is measured
US grants placed by each grantee’s ZIP, which can differ from where services are delivered. Need from public data (U.S. Census/ACS, CDC PLACES, Eviction Lab, USDA), shown as context about the area, never attributed to the funder’s giving.
03Its grantees
repeat funding

Who it funds again

Organizations funded in more than one year, against those funded once.

83%of every dollar goes to organizations it has funded before.
$590k · 6 repeat orgs$117k to everyone else

6 repeat relationships: 3 still active in FY2025, 3 since wound down; 1 grantees were first funded in FY2025 (too recent to call).

How the two cohorts compare

Re-uppedFunded once

Organizations

6
14

Total granted

$590k
$116k

Median revenue growth · since first grant

-2%
0%

Still filing today

50%
43%

New vs renewed · share of each year

In FY2025, 96% of grant dollars renewed an existing relationship; $1k went to new ones.

50%100%’17’18’19’20’21’22’23’24’25
RenewedFirst-time

Where new relationships form · theme of each grantee’s first grant

’17’18’19’20’21’22’23’24’25
HealthEducationInternationalPhilanthropyEnvironmentFood & NutritionOther
How this is measured
First-time means a grantee’s first year in the filing window; renewed means funded in an earlier year too. The renewed share climbs naturally as a portfolio matures, so the signal is a year that bucks it (a wave of new grantees). The earliest year is left-censored: relationships that predate the data read as new. Theme is the grantee’s IRS cause.

Backed again, and grew

  • GA
    GUSTAVUS ADOLPHUS COLLEGE
    6× · 2017–2024 · $280k · revenue -3%
  • CM
    Cheyenne Mountain Zoo
    5× · 2017–2022 · $250k
  • CH
    Children's Hospital Colorado
    2× · 2024–2025 · $20k

Funded once

  • MM
    MINNESOTA MASONIC CHILDREN'S CLINIC FOR COMMUNICATION DISORDERS
    one grant, 2017 · $50k · revenue -74%
  • EE
    EXPLORE ECOLOGY
    one grant, 2024 · $10k · revenue 0%
  • CH
    Children's Hospital Colorado Foundationgraduated
    one grant, 2020 · $10k · revenue +26%
How this is measured

Repeat means funded in two or more distinct years. Growth and survival are read from each grantee’s own subsequent IRS filings.

04Its field

Closest unfunded matches

The nonprofits that most resemble its grantees but are not funded by it, scored along the direction from the rest of the field toward the portfolio. A resemblance in what they say they do, not a recommendation.

1
Minnesota Council on Foundations

MCF is a vibrant philanthropic community connecting, strengthening and mobilizing the power of philanthropy to advance prosperity and equity.

—
2
Colorado Museum of Natural History

Be a catalyst! Ignite our community's passion for nature and science.

Arts & Culture
3
Breck School

We create confident learners who lead lives of intellectual curiosity, self-knowledge, and social responsibility.

Education
4
Care Providers of Minnesota Foundation

To promote quality care in long term health care facilities through education and research.

—
5
Set of Colorado Springs

S.e.t. of colorado springs is made up of a small multi-skilled staff and a large corps of volunteers, including many in the medical professions. s.e.t. of colorado springs collaborates with other care-givers in the pikes peak area to teach…

—
6
Goodwill Industries of Denver

Goodwill's mission is to provide education, career development, and employment opportunities to help coloradans in need achieve self-sufficiency, dignity, and hope through the power of work.

—
7
Massachusetts Institute of Technology

The mission of mit is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the 21st century.

Education
8
President and Trustees of Bates College

Bates is a college of the liberal arts and sciences, and is a coeducational, nonsectarian, residential college with special commitments to academic rigor, and to assuring in all of its efforts the dignity of each individual, and access to…

Education
9
National Association for College Admission Counseling

Empowering college admission counseling professionals through education, advocacy, and community.

Education
10
Minnesota Medical Association

To be the leading voice of medicine to make minnesota the healthiest state and the best place to practice.

—
11
Pathways Hospice

Honoring every moment of life, pathways hospice provides compassionate, excellent, comprehensive care for those who have an advanced medical condition and those who are grieving.

Human Services
12
The Chicago School of Professional Psychology

The Chicago School educates the next generation of change-makers in innovative theory and culturally competent practice to strengthen the integrated health of individuals, organizations, and communities.

Education
How this is measured
The grantee most central to the portfolio’s shape is Goodwill of Colorado; the most unlike its peers is Trekking for Kids Inc. Resemblance is measured on each organization’s own IRS 990 mission text; it reflects how work is described, not its quality or impact.
04the grantee network

10 grantees tracked through their own filings, 2017–2025.

Each grant beside the grantee’s revenue from every source, year by year.

How this is measured

Counted here: distinct organizations funded across 2017 to 2025, not grant rows in a single year, so this will not match the grant count on the cover. 10 of the 21 grantees resolved in that span have returns of their own we could reconcile.

Each grantee is resolved to its own IRS returns. Association, dated; never a causal claim.

0
Load-bearing (≥25% of a budget)
0
Early backer (in before they grew)
9/10
Grantees still filing
4/10
Grew since first funded

Where the money sits, by cause and then by grantee

Cheyenne Mountain Zoo: $250,000 · OtherCheyenne Mountain ZooChildren's Hospital Colorado: $20,000 · OtherChildren's Hospital ColoradoSt Paul Catholic Church: $17,500 · Other+9 more: $41,919 · Other+9 moreGUSTAVUS ADOLPHUS COLLEGE: $280,000 · EducationGUSTAVUS ADOLPHUS COLLEGEMINNESOTA MASONIC CHILDREN'S CLINIC FOR COMMUNICATION DISORDERS: $50,000 · HealthMINNESOTA…Children's Hospital Colorado Foundation: $10,000 · HealthChildren'…+1 more: $2,000 · HealthSTARABILITY FOUNDATION INC: $20,000 · PhilanthropyEXPLORE ECOLOGY: $10,000 · EnvironmentTREKKING FOR KIDS INC: $2,500 · InternationalGoodwill of Colorado: $1,300 · EmploymentCare and Share Inc: $1,000 · Food & Nutrition
Other$329,419Education$280,000Health$62,000Philanthropy$20,000Environment$10,000International$2,500Employment$1,300Food & Nutrition$1,000

Each grantee by its size and the funder’s share of it; top left is load-bearing

25%50%75%100%$1.0M$10M$100Mgrantee revenue →↑ funder's share of their budgetGUSTAVUS ADOLPHUS COLLEGE: $280,000 over 6y, 0.1% of budgetSTARABILITY FOUNDATION INC: $20,000 over 2y, 0.1% of budgetEXPLORE ECOLOGY: $10,000 over 1y, 0.5% of budgetChildren's Hospital Colorado Foundation: $10,000 over 1y, 0.0% of budgetTREKKING FOR KIDS INC: $2,500 over 1y, 0.7% of budgetNAMI National: $2,000 over 2y, 0.0% of budgetColorado Springs Fine Arts Center: $1,919 over 1y, 0.5% of budgetGoodwill of Colorado: $1,300 over 1y, 0.0% of budgetCare and Share Inc: $1,000 over 1y, 0.0% of budget
Grantee by grantee: a decade per organization, before and after funding

A decade per grantee: revenue shaded, grants as bars, all rows on one timeline.

  • Who funds GUSTAVUS ADOLPHUS COLLEGE ↗
  • Who funds MINNESOTA MASONIC CHILDREN'S CLINIC FOR COMMUNICATION DISORDERS ↗
  • Who funds STARABILITY FOUNDATION INC ↗
  • Who funds EXPLORE ECOLOGY ↗
  • Who funds Children's Hospital Colorado Foundation ↗
  • Who funds TREKKING FOR KIDS INC ↗
  • Who funds NAMI National ↗
  • Who funds Colorado Springs Fine Arts Center ↗
  • Who funds Goodwill of Colorado ↗
  • Who funds Care and Share Inc ↗

Co-funders

Grantmakers whose grantees overlap with this funder’s far more than size alone predicts. Closer means stronger alignment; arcs show where they also fund each other. Here they form a tightly interlocked group: most of these funders back each other's grantees too.

National Philanthropi…Fidelity Investments …Amazonsmile Foundation
National Philanthropic TrustPA8.7× affinity4 shared granteesties to 2 of 2Hover any node to trace its alignments.Compare side by side →

Open a dossier: National Philanthropic Trust · Fidelity Investments Charitable Gift Fund · Amazonsmile Foundation

How this is measured
Affinity is a Gamma-Poisson posterior co-funding rate, re-centered on the typical rate, so thin evidence shrinks toward no signal. Overlap is association, not proof of shared intent.

How much its grantees rely on government

Each dot is one organization Corundum Foundation funds: left to right is the share of its income from government, bottom to top the share from Corundum Foundation. Bigger dots raise more.

2024
’20’21’22’23’24’25
no gov · 10%0%1%3%5%funder's share of their income ↑0%3%5%8%10%share of the org’s income from government →
    no gov moneyreceives it· size = income
    1get no government money at all
    2report government grants on their 990 we could not trace to a source (not plotted)
    0rely on government for over half their income
    ⤢ axis zoomed · 0–10%
    typical government reliance, FY20–25
    How this is measured
    Government income is each org’s traced federal awards (USASpending grants and contracts) plus state payments (open checkbooks) as a share of its total revenue (IRS Form 990); the self-reported government-grant line (990 line 1e) is carried for cross-check: a grantee that reports government grants we could not trace to a source is left off the chart rather than shown as receiving none. An association, not a claim that a grant caused the public funding. Coverage is precision-first, a floor rather than a census; state records exist for 9 states, so a grantee outside them shows no state figure (dimmed) rather than a false zero. Federal award amounts are obligations, which can span years, so a single-year share is indicative. 990 filings lag 12 to 24 months.
    05Through Plinth

    Warm introductions · Powered by PlinthPlus

    How do I get to Corundum Foundation?

    Find your warmest path to Corundum Foundation through trustees and officers whose names appear on both boards. Search for your organization and Plinth traces the shortest route it can evidence.

    Each link is a name appearing on two organizations’ public IRS 990 filings, matched on that name and, where the filings support it, on location. A same-state match has geographic support, which is a second matching feature rather than confirmation that the two are one person; a cross-state one is the likeliest to be two people who share a name. Every hop shows its tier, low-confidence and distant paths are held back rather than guessed, and it is worth confirming the person before you use the introduction.

    On method. Every financial figure here is read from IRS e-file XML, the funder’s own 990/990-PF, and from the multi-year returns of the 21 grantees we resolved, each linked to its source. Grantee outcomes are each organization’s own program-service reporting (Form 990, Part III), read as association with funding, never as caused by it. Low-confidence name matches are suppressed rather than guessed. How we build these →

    How this is measured
    Each figure carries one of six labels. Filed is what the funder reported on its return. Official is another government record about an organization, such as a federal award or a charity register, joined by name where no shared identifier exists. Resolved is an identity we worked out where the filing named a recipient without an EIN, kept only above a measured confidence threshold. Computed is arithmetic over those, like themes, portfolio clusters and co-funder strength. Context is a statistic about a place rather than about an organization, which is what the need overlay is: it describes the area a grantee’s address sits in, not where its work lands. Inferred is drawn by a model from text, like the partnerships read out of public news and organization websites. Each is labeled where it appears.

    Generated from the IRS Form 990-PF e-file return for fiscal year 2025, released 2025. Filings run roughly 12 to 24 months behind; figures are dated accordingly.

    Source object · view filing

    Play a game based on Corundum’s filings →

    More from the funding graph

    The unnamed billions
    grants reported with no recipient in the public record
    The regranting layer
    51% of grant dollars land in the regranting layer
    The DAF merry-go-round
    $9.7B circulates between donor-advised funds
    The endowment market
    who holds foundation money, and what just moved
    The camps
    funders cluster by geography, not ideology
    By state
    where grant money is based, and what stays home